Search

Background: p‐Phenylenediamine (PPD) is a potent contact allergen found in many hair colour products. However, not all individuals develop allergic contact dermatitis (ACD) although they are regularly exposed to PPD. It is unclear whether these asymptomatic individuals are true non‐responders to PPD or whether they mount a response to PPD without showing any symptoms. Methods: Skin biopsies were collected from 11 asymptomatic hairdressers regularly exposed to PPD and from 10 individuals with known ACD on day 4 after patch testing with 1% PPD in petrolatum and petrolatum exclusively as control. RNA sequencing and confocal microscopy were performed. Results: T cell activation, inflammation and apoptosis pathways were up‐regulated by PPD in both asymptomatic and allergic individuals. Compared to asymptomatic individuals with a negative patch test, individuals with a strong reaction to PPD strongly up‐regulated both pro‐ and anti‐inflammatory cytokines genes. Interestingly, PPD treatment induced significant up‐regulation of several genes for chemokines, classical type 2 dendritic cell markers and regulatory T cell markers in both asymptomatic and allergic individuals. In addition, apoptosis signalling pathway was activated in both non‐responders and allergic individuals. Conclusion: This study demonstrates that there are no true non‐responders to PPD but that the immune response elicited by PPD differs between individuals and can lead to either tolerance, subclinical inflammation or allergy. [ABSTRACT FROM AUTHOR]

Background: Textile dye mix (TDM) is included in the European baseline series (EBS), but it is unknown if TDM identifies all patients with a textile dye allergy. Objectives: To assess the added value of performing patch testing with individual textile dyes in addition to TDM. Methods: Two hundred and nine patients suspected to have a contact allergy to textile dyes were patch tested between January 2015 and December 2021 with the EBS, as well as an individual textile dye test series containing textile dyes part of TDM (TDM‐dyes) and outside the scope of TDM (non‐TDM dyes). Results: Fifty‐four patients (25.8%) tested positive for TDM or an individual textile dye. Disperse Orange 3 (9.6%) followed by Disperse Blue 106 (4.8%) were the most common individual textile dyes causing a positive patch test reaction. Of the 54 dye positive patients, 28 (51.9%) had a clinically relevant reaction. No clinically relevant reactions were seen in patients that solely tested positive for non‐TDM dyes. Conclusions: It is beneficial to test individual textile dyes in addition to TDM in patients suspected of having a textile dye allergy. Otherwise, 46.3% of the dye positive patients and 35.7% of the patients with a clinically relevant reaction would have been missed. [ABSTRACT FROM AUTHOR]

Sarcoidosis is a systemic inflammatory disorder characterized by the formation of non‐caseating granulomas. Cutaneous involvement of sarcoidosis is common and has a wide variety of clinical presentations. Herein, we present a case of cutaneous sarcoidosis mimicking pigmented purpuric dermatosis (PPD) in a 26‐year‐old female treated with topical tofacitinib cream and a literature review of all other reported cases of cutaneous sarcoidosis with PPD‐like features. [ABSTRACT FROM AUTHOR]

Keywords: allergic contact dermatitis; Alopecia areata; case report; hair dye; hair loss; henna tattoos; multiple sclerosis; non-scarring alopecia; PPD; p-phenylenediamine EN allergic contact dermatitis Alopecia areata case report hair dye hair loss henna tattoos multiple sclerosis non-scarring alopecia PPD p-phenylenediamine 536 539 4 11/11/22 20221201 NES 221201 Several types of alopecia may be triggered by scalp allergic contact dermatitis (ACD) including telogen effluvium1 and scarring alopecia.2 We hereby describe an unusual case of alopecia areata (AA) activated by severe ACD to a permanent hair dye. Two years after the events of ACD and AA, the patient was subsequently diagnosed with multiple sclerosis (MS). In predisposed individuals, MS may be diagnosed prior to or after AA.10 AA may also be triggered by alemtuzumab, a therapy used in MS. [Extracted from the article]

Background: Warts are common in children and can be difficult to treat. Many treatments for warts are destructive and painful in contrast to intralesional immunotherapy using different types of antigens. Aim: To evaluate the efficacy, safety, and tolerability of intralesional purified protein derivative (PPD) versus intralesional zinc sulfate 2% in the treatment of pediatric warts. Methods: This randomized clinical trial included 120 children with multiple warts divided into two equal groups. Group Ⅰ received intralesional 10 IU (0.1 ml) of PPD, group Ⅱ received intralesional zinc sulfate 2% in the largest wart every 2 weeks till improvement or for a maximum five treatment sessions. The follow‐up period was 6 months after the last treatment session. Results: The overall response was equal in both groups (81.7%), but the response of the injected wart was higher in the zinc sulfate group (93.4%) versus PPD group (83.3%) with no significant difference. The highest cure rates were after the 5th session in the PPD group and the 1st session in the zinc sulfate group with slightly lower numbers of sessions needed for cure in the zinc sulfate group (3 sessions) versus the PPD group (4 sessions). The zinc sulfate group showed statistically significant higher rates of complications (pain, inflammation, necrosis, and scar) than PPD group. The zinc sulfate group showed non‐significant higher rates of recurrence during the follow‐up period. Conclusion: Both intralesional PPD and zinc sulfate 2% are effective in pediatric warts with higher safety profile of PPD. [ABSTRACT FROM AUTHOR]

Objective: The aim of the study is to examine the risk of postpartum depression (PPD) among women who delivered during the COVID-19 pandemic compared to women who delivered before the COVID-19 pandemic and how economic challenges are associated with PPD. Methods: Data were collected from 2332 women. This includes 1197 women from healthcare facilities in 2019 who were followed up at 2-4 and 10 weeks postpartum. Additionally, we recruited 1135 women who delivered from March 16, 2020 onward when COVID-19 restrictions were mandated in Kenya in the same catchment areas as the original sample to compare PPD rates. Results: Adjusting for covariates, women who delivered during COVID-19 had 2.5 times higher odds of screening positive for PPD than women who delivered before COVID-19 (95% confidence interval [CI] 1.92-3.15). Women who reported household food insecurity, required to pay a fee to cover the cost of PPE during labor and delivery and/or postnatal visit(s), and those who reported COVID-19 employment-related impacts had a higher likelihood of screening for PPD compared to those who did not report these experiences. Conclusion: The COVID-19 pandemic has greatly increased the economic vulnerability of women, resulting in increases in PPD. [ABSTRACT FROM AUTHOR]

Background: Cutaneous warts are frequent conditions that possess much challenge to treat. Objective: To evaluate safety and efficacy of intralesional injection of tuberculin purified protein derivative (PPD) antigen injection vs MMR (mumps, measles, rubella) antigen for the treatment of multiple warts. Methods: The study included 90 Patients who were divided into three groups (A, B, and C). Each group consisted of (30) patients. Group (A) subjects received intralesional PPD injections. Group (B) subjects received intralesional MMR antigen injection and Group (C) received intralesional saline injection. Results: Full clearance of warts was observed in 18 (60%) of patients in group (A) (70%) vs 24 patients (80%) in group (B). Distal warts completely disappeared in 18 (60%) of patients in group A and 12 (40%) of patients in group B. Infrequent side effects including pain, erythema, and minimal induration were reported in both groups. Conclusion: We established a good safety and efficacy profile for tuberculin PPD and MMR antigens in resistant wart treatment. [ABSTRACT FROM AUTHOR]

The present paper reports on an experimental study performed in a seminar room of the University of Luxembourg in a building of the 1970ies without a major renovation. This lecture room is typical for this building period and has a capacity of 60 seats. It is equipped with a mechanical ventilation system that is normally in operation on workdays for 11 hours a day in semester periods (8:00–19:00h), while windows can be opened manually. A blower‐door test revealed that the room is not airtight. During a year, the ventilation system was shut "on" and "off" in periods of some weeks and the consumed final‐energy was measured, as well as the indoor climate assessed by physical and psychological measurements. For instance, the measured CO2 concentrations are marginally better with the ventilation system „on", which was not perceived in any way by the occupants during the investigations. It was not possible to properly identify the impact of ventilation on the consumed heat‐energy, as the room could not be thermally separated from the rest of the building. But with the system "on", there was a clear increase in consumed primary energy due to the electric consumption of the fans. No relationship between the perceived percentage of dissatisfied and perceived climate could be observed. It is concluded that the typical normal operation modus is questionable for seminar rooms in older buildings with variable occupancy and that a simple shut down or semi‐automatic user‐controlled modus by low‐cost retrofit seems advantageous. [ABSTRACT FROM AUTHOR]

Pigmented purpuric dermatosis (PPD) is a skin disorder mainly seen in the lower limbs. The nanofibrous web has been shown to be an appropriate alternative for the treatment of skin diseases as a drug delivery vehicle. In this study, sodium alginate (SA)/polyethylene oxide (PEO) nanofibers containing vitamin C (VC) were fabricated using both blended electrospinning and core/shell electrospinning. The resultant nanofibers were characterized using Fourier transform infrared spectroscopy and scanning electron microscopy. Enhancing the VC content resulted in increasing the nanofibers diameter. Also, the degradation rate and drug release were investigated. Drug release was evaluated using the in vitro dissolution and permeation method. The degradation rate and the drug release of the core/shell nanofibers were found to be lower than those of the blended nanofibers. The drug release of the extended nanofibers followed a different pattern, indicating that the extension of the nanofibers could be a promising way to control the drug release. [ABSTRACT FROM AUTHOR]

Background: There is an ongoing discussion on whether routinely patch testing with p‐phenylenediamine (PPD) 1.0% pet. is safe, owing to the risk of patch test sensitization. Late‐appearing patch test reactions may reflect patch test sensitization, but may also be attributable to a low degree of pre‐existing sensitization. Objectives: To follow the positive patch test reactions to PPD and its salt PPD dihydrochloride (PPD‐DHC) in order to characterize reaction patterns concerning time and dose in PPD‐sensitized individuals. Methods: Volunteers with previous reactions to PPD 1.0% were included and patch tested with PPD and PPD‐DHC in equimolar dilution series. There were then seven follow‐up visits over a period of 28 days. Results: Twenty‐six volunteers completed the study, of whom 23 of 26 (88%) reacted to PPD 1.0%, and 69% reacted to PPD 0.32%. Altogether, 42% and 27% reacted to the corresponding equimolar concentrations of PPD‐DHC. After day 7, no new reactions were observed to any concentration tested, either of PPD or of PPD‐DHC. Conclusion: No late‐appearing reactions to PPD or PPD‐DHC were observed at any dose. There is a risk of missing contact allergy when the dose is decreased. [ABSTRACT FROM AUTHOR]

Summary: Flowering time is an important factor affecting grain yield in wheat. In this study, we divided reproductive spike development into eight sub‐phases. These sub‐phases have the potential to be delicately manipulated to increase grain yield. We measured 36 traits with regard to sub‐phase durations, determined three grain yield‐related traits in eight field environments and mapped 15 696 single nucleotide polymorphism (SNP, based on 90k Infinium chip and 35k Affymetrix chip) markers in 210 wheat genotypes. Phenotypic and genetic associations between grain yield traits and sub‐phase durations showed significant consistency (Mantel test; r = 0.5377, P < 0.001). The shared quantitative trait loci (QTLs) revealed by the genome‐wide association study suggested a close association between grain yield and sub‐phase duration, which may be attributed to effects on spikelet initiation/spikelet number (double ridge to terminal spikelet stage, DR‐TS) and assimilate accumulation (green anther to anthesis stage, GA‐AN). Moreover, we observed that the photoperiod‐sensitivity allele at the Ppd‐D1 locus on chromosome 2D markedly extended all sub‐phase durations, which may contribute to its positive effects on grain yield traits. The dwarfing allele at the Rht‐D1 (chromosome 4D) locus altered the sub‐phase duration and displayed positive effects on grain yield traits. Data for 30 selected genotypes (from among the original 210 genotypes) in the field displayed a close association with that from the greenhouse. Most importantly, this study demonstrated specific connections to grain yield in narrower time windows (i.e. the eight sub‐phases), rather than the entire stem elongation phase as a whole. [ABSTRACT FROM AUTHOR]

SUMMARY: Background: Concern about causing active sensitization when patch testing is performed with p‐phenylenediamine (PPD) 1% pet. has led to a recommendation to use PPD 0.3% pet. as a potentially safer preparation. However, the dose per area of allergen delivered, and hence the risk of active sensitization, depend on the amount dispensed into the patch test chamber, which can vary widely. Objective: To evaluate whether patch testing with equivalent doses of different concentrations of PPD in pet. is associated with similar outcomes. Methods: Seventeen known PPD‐sensitive subjects were patch tested with different volumes and concentrations of PPD in pet. that deliver the same allergen dose per unit area (6 mg of PPD 1% pet. and 20 mg of PPD 0.3% pet. in Finn Chambers®, both equivalent to ∼ 0.09 mg/cm2). Results: Eleven patients (65%) had positive reactions to both doses; 4 patients (24%) had negative results [percentage agreement of 88% (15/17)]. One patient each had a positive reaction to only one dose. Conclusions: The 88% concordance suggests that dose per unit area is more important in determining reactions to allergens than the excipient volume dispensed. Patch testing with a smaller volume of 1% PPD may be a reasonable alternative to testing with 20 mg of 0.3% PPD. [ABSTRACT FROM AUTHOR]

Progressive pseudorheumatoid dysplasia (PPD) is a rare autosomal recessive disorder characterized by spondyloepiphyseal dysplasia associated with pain and stiffness of multiple joints, enlargement of the interphalangeal joints, normal inflammatory parameters, and absence of extra-skeletal manifestations. Homozygous or compound heterozygous WISP3 mutations cause PPD. We report two siblings from a non-consanguineous Ecuadorian family with a late-onset spondyloepiphyseal dysplasia. Mutation screening was undertaken in the two affected siblings using a customized skeletal dysplasia next generation sequencing (NGS) panel and confirmed by Sanger sequencing. Two compound heterozygous mutations were identified in WISP3 exon 2, c.[190G>A];[197G>A] (p.[(Gly64Arg)];[(Ser66Asn)]) in the two siblings, both of which had been inherited. The p. (Gly64Arg) mutation has not been previously described whilst the p. (Ser66Asn) mutation has been reported in two PPD families. The two siblings presented with atypical PPD, as they presented during late childhood, yet the severity was different between them. The progression was particularly aggressive in the male sibling who suffered severe scoliosis by the age of 13 years. This case reaffirms the clinical heterogeneity of this disorder and the clinical utility of NGS to genetically diagnose skeletal dysplasias, enabling adequate management, monitorization, and genetic counseling. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Background The results from a previous study indicated the presence of several possible sensitizers formed during oxidation of the potent sensitizer p-phenylenediamine ( PPD) to which PPD-sensitized patients might react, in various patterns. Objectives To extract and analyse a yellow spot from a thin-layer chromatogram with oxidized PPD, to which 6 of 14 (43%) PPD-positive patients had reacted in a previous study, in order to identify potential sensitizer(s) and to patch test this/these substance(s) in the 14 PPD-positive patients. Methods The yellow spot was extracted from a thin-layer chromatogram of oxidized PPD, and two substances, suspected to be allergens, were identified by analysis with gas chromatography mass spectrometry ( GCMS). The 14 PPD-positive patients, who had been previously tested with the thin-layer chromatogram of oxidized PPD, participated in the investigation, and were tested with dilutions of the two substances. Results GCMS analysis identified 4-nitroaniline and 4,4′-azodianiline in the yellow spot. Of the 14 PPD-positive test patients, 5 (36%) reacted to 4-nitroaniline and 9 (64%) reacted to 4,4′-azodianiline. Conclusion The results show that 4-nitroaniline and 4,4′-azodianiline, formed during oxidation of PPD, are potent sensitizers. PPD-sensitized patients react to a high extent to concentrations equimolar to PPD of 4-nitroaniline and 4,4′-azodianiline. [ABSTRACT FROM AUTHOR]

Im Rahmen zahlreicher Veröffentlichungen und Forschungsvorhaben zu Fragen der Energieeinsparung, der Ressourceneffizienz und dem nahezu allumfassenden Thema der Nachhaltigkeit wird häufig auch der Begriff der 'Behaglichkeit' als ein Teilaspekt der genannten Themengebiete aufgeführt. Es mehren sich Beiträge, in denen ausgeführt wird, dass die Qualität der Arbeitsumgebung - und damit verbunden die Zufriedenheit der Nutzer - in Büro- und Verwaltungsgebäuden eng mit deren Produktivität verbunden ist. Es wurde erkannt, dass im Laufe des Lebenszyklus einer Immobilie die vorhandenen Personalkosten alle anderen Gebäudekosten (einschließlich der Kosten für die Errichtung und den Betrieb eines Gebäudes) um ein Mehrfaches übersteigen. Mangelnde Qualität des Arbeitsplatzes ist damit für Investoren und Immobilienverwalter durchaus ein Faktor, der die Rentabilität eines Objektes nachteilig beeinflussen kann. Nicht zu vernachlässigen ist dieser Aspekt insbesondere vor der Tatsache eines Überangebots von (älteren) Büroflächen in Ballungsgebieten. Dabei ist die thermische Behaglichkeit oder der thermische Komfort zunächst einmal ein indifferenter Körperzustand, bei dem weder ein übermäßiges Gefühl von Kälte (Frieren) noch von Wärme (Schwitzen) vorhanden ist. Mit thermischer Behaglichkeit wird demzufolge der Zusammenhang zwischen physiologischen Zuständen und Empfindungen von Personen beschrieben. Dieser Zusammenhang ist für die Bewertung des thermischen Komforts von großer Bedeutung, weil das Ziel von Investoren, Immobilienbesitzern und -verwaltern subjektiv zufriedene Nutzer sein müssen. Eine solche Zufriedenheit lässt sich durch geeignete objektive Untersuchungen und darauf abgestimmte bauliche und anlagentechnische Maßnahmen erreichen. Das Ziel der nachstehend beschriebenen Arbeit sind Untersuchungen zur Frage, wie 'Behaglichkeit' in genutzten Bürogebäuden mit einfachen Mitteln erfasst und bewertet werden kann und wie sich daraus Maßnahmen ableiten lassen, die zu einer ggf. erforderlichen Verbesserung der vorgefundenen Arbeitsplatzqualität führen. Dazu werden zunächst die in Normen und Richtlinien definierten Kriterien der Behaglichkeit angewendet und hinsichtlich der vorhandenen Bewertungsverfahren für eine vereinfachte Anwendung in der Praxis untersucht. Die gewonnenen theoretischen Erkenntnisse zur Behaglichkeit werden anschließend für bestehende Bürogebäude angewendet und verifiziert. Thermal comfort according to DIN EN ISO 7730 - A simplified method to collect and calculate data for the evaluation of commercial buildings. In numerous publications and research projects concerning energy conservation, resource efficiency, and the almost universal field of sustainability, the term 'comfort' is often mentioned as a partial aspect of the named topics. There are a growing number of scientific papers in which the quality of work environment in office buildings - and with this the associated user satisfaction - is closely linked to the productivity of the workforce. It was found, that during the lifecycle of a commercial building the employee costs exceed the total costs of the building (including costs for planning, construction and operation of the building) by several times. Therefore, a lack of quality in the work environment is a factor that investors and property managers will consider and that might also have a negative effect for the profitability of an object. Especially in urban areas with a growing oversupply of (aging) office spaces this aspect has to be considered. First of all, thermal comfort is an indifferent body condition in which neither an excessive feeling of cold (freezing) or heat (sweating) is given. In this context, thermal comfort describes the relationship of different physiological states and the more or less subjective feelings of humans. This fact is of great importance for the evaluation of thermal comfort, because the goal of investors, property owners and managers must be satisfied users (in their subjective measure). Such satisfaction can be achieved through appropriate objective investigations of the indoor environment and valid constructional and technical measures. The target of the following paper was to investigate how 'comfort' can be described and measured in existing office buildings by simple means, and how measures can be derived that might lead to an improvement of the work environment quality. Therefore, in a first step the criteria of comfort, defined in certain standards and guidelines, were analyzed with regard to evaluation methods for an application in practice. Then, the theoretical findings for the evaluation of comfort were used in existing office buildings and reviewed. [ABSTRACT FROM AUTHOR]

Background Hair dye exposure is the most common cause of sensitization to p-phenylenediamine ( PPD). Cross-reactions with structurally related allergens occur. Objectives It is suggested that a stronger patch test reaction (3+ rather than 1+) to PPD (usually tested as 1% petrolatum) is associated with an increased propensity for cross-reactions. In this article we will demonstrate this association. Methods Of 230 patients with allergic reactions to PPD on patch testing identified during 2007-2012 from clinical records, notes for 221 were available for review. Data were collected regarding age, sex, and grade of reaction [International Contact Dermatitis Research Group ( ICDRG) criteria] to PPD. Cross-reactions with the following allergens, found in our baseline series, were recorded: Disperse Yellow 3, N-isopropyl- N ′-phenyl- p-phenylenediamine ( IPPD), and caine mix. Having excluded 23 doubtful reactions, the reactions from 198 patients were further considered. Results Of the patients, 75.3% (n = 149) were female, and the mean age was 48.6 years (12-82 years). Of the patients allergic to PPD, 16.6% (n = 33) showed cross-reactions with one or more related allergens. Cross-reactions were seen in 16% with a grade of 1+, 14.5% with a grade of 2+, 28.6% with a grade of 3+ when PPD was tested 1% pet., and 50.0% when PPD was tested at 0.1-0.001%, arbitrarily considered to be 4+ ( p = 0.02; Cramér's V = 0.23). Conclusion An increasing likelihood of reactions to Disperse Yellow 3, IPPD or caine mix was seen with increasing strength of patch test reaction to PPD. The clinical relevance of these cross-reactions is unclear. [ABSTRACT FROM AUTHOR]

The Genital warts are common sexually transmitted diseases caused by definite types of human papillomavirus. There are many strategies for the treatment of genital wart and intralesional immunotherapy is considered to be a safe and effective treatment modality. However, there are lack of studies that comparing the clinical effectiveness of intralesional purified protein derivative (PPD) and Candida antigen (CA) in genital wart treatment. To investigate the effectiveness and safety of PPD and CA in the treatment of genital warts. Eighty patients were enrolled in this study and were randomly divided into 2 groups with 40 patients in each. Each antigen was injected intralesionally at a dose of 0.1 ml into the largest wart every 2 weeks until complete improvement or for a maximum of four sessions. Complete clinical response was demonstrated in 65%, 62.5% in PPD and CA groups, respectively. There was no statistically difference between both groups. After the 3-month follow-up period, 72.5%, 85% of patients showed complete clearance in PPD and CA groups respectively. Side effects were mild and insignificant in both groups. Recurrence was observed in only one patient in each group. Immunotherapy by intralesional PPD and CA injection is considered to be effective and well-tolerated modalities in treatment of genital wart with minimal side effects and recurrence rate compared to other modalities., (© 2022 Wiley Periodicals LLC.)

Background p-Phenylenediamine ( PPD) is the primary patch test screening agent for hair dye contact allergy, and approximately 100 different hair dye chemicals are allowed. Objectives To examine whether PPD is an optimal screening agent for diagnosing hair dye allergy or whether other clinically important sensitizers exist. Methods Two thousand nine hundred and thirty-nine consecutive patients in 12 dermatology clinics were patch tested with five hair dyes available from patch test suppliers. Furthermore, 22 frequently used hair dye ingredients not available from patch test suppliers were tested in subgroups of ∼ 500 patients each. Results A positive reaction to PPD was found in 4.5% of patients, and 2.8% reacted to toluene-2,5-diamine ( PTD), 1.8% to p-aminophenol, 1% to m-aminophenol, and 0.1% to resorcinol; all together, 5.3% (n = 156). Dying hair was the most frequently reported cause of the allergy (55.4%); so-called 'temporary henna' tattoos were the cause in 8.5% of the cases. p-Methylaminophenol gave a reaction in 20 patients (2.2%), 3 of them with clinical relevance, and no co-reaction with the above five well-known hair dyes. Conclusions Hair dyes are the prime cause of PPD allergy. PPD identifies the majority of positive reactions to PTD, p-aminophenol and m-aminophenol, but not all, which justifies additional testing with hair dye ingredients from the used product. [ABSTRACT FROM AUTHOR]

Wu X, Liang Y, Wang L, Wang Z, Zhang C, Yang Y, Zhang J. Latent tuberculosis infection among new recruits to the army in Beijing, China in 2009. APMIS 2011; 119: 377-84. China is a country with high latent tuberculosis infection (LTI) and has a policy of routine BCG vaccination. To monitor tuberculosis (TB) infection, a total of 907 new recruits to the army were interviewed and routinely examined by chest radiographs. They were intradermally injected with purified protein derivative (PPD) and detected with enzyme-linked immunospot (ELISPOT) assay with recombinant CFP-10/ESAT-6 (rCFP-10/ESAT-6) fusion protein, as a stimulus, from December 2009 to February 2010. The prevalence of LTI among new recruits was estimated as 50.2% and 30.7% by PPD skin test and ELISPOT assay, respectively. Of 452 PPD-negative and 455 PPD-positive volunteers, 132 (29.2%) and 146 (32.1%) were ELISPOT positive, respectively. The overall consistency between these two tests was 51.4% (466/907). Although 65.6% of PPD-positive volunteers and 27.8% of ELISPOT-positive volunteers (spot-forming cells; SFC 12.2 ± 21.2) could find the vaccination scars on their arms, 21.3% of PPD-positive volunteers and 35.9% of ELISPOT-positive volunteers (SFC 18.3 ± 34.6) could not. Thus, the TB infection rate in army recruits in China was not as high as previously reported. The results suggest that the ELISPOT technique, we presented, is an accurate method for screening TB infection in China. [ABSTRACT FROM AUTHOR]

p-Phenylenediamine (PPD) 1% in petrolatum has been shown in a prospective study to elicit late reactions in 1.5% of routine patch tests, which may be indicative of patch test sensitization. To assess the frequency of late reactions to reduced PPD patch test concentrations. In 1838 patients, PPD was tested at three concentrations (0.5% pet., group I; 0.4% pet., group II; and 0.35% pet., group III). Patch tests were read on D1 (D2) to D3 (D4); additional late readings were performed on D7, D14, and D21. Patients who were not able to return for all scheduled late readings were telephoned on D7, D14, and D21, and questioned about a reaction at the patch test sites. Data of 1666 patients (1069 women and 597 men) were eligible. Late reactions were observed in 9 patients, 3 in group I (0.49%) and 5 in group II (0.63%). In 7 of 8 of the patients with late reactions, patch tests were applied for 48 hr. On retesting, 4 of 5 patients became positive at D2 or D3. The occurrence of late reactions to PPD may be influenced by patch test concentration and duration. PPD 0.4-0.5% pet. may cause late reactions indicative of active sensitization. [ABSTRACT FROM AUTHOR]

Purpose: To determine the effect of steroid treatment on visual outcome and ocular complications in patients with presumed ocular tuberculosis. Methods: Retrospective review of patients with presumptive ocular tuberculosis. The clinical diagnosis was made based on ocular findings, positive purified protein derivative (PPD) testing of more than 15 mm induration, exclusion of other causes of uveitis and positive ocular response to anti-tuberculous therapy (ATT) within 4 weeks. Group 1 included patients who had received oral prednisone or subtenon injection of triamcinolone acetonide prior to ATT. Group 2 included patients who did not receive corticosteroid therapy prior to administration of ATT. Results: Among 500 consecutive new cases of uveitis encountered in 1997-2007 there were 49 (10%) patients with presumed ocular tuberculosis. These comprised 28 (57%) male and 21 (43%) female patients with a mean age of 45 years (range 12-76 years). Four (20%) patients in group 1 had initial visual acuity of 20 / 40 or better, in comparison to eight (28%) patients in group 2. At 1-year follow-up, six (30%) patients in group 1 had a visual acuity of 20 / 40 or better compared with 20 (69%) patients in group 2 (p = 0.007). Of 20 eyes (26%) in group 1 that had visual acuity of < 20 / 50 at 1-year follow up, 14 (70%) eyes developed severe chorioretinal lesion (p = 0.019). Conclusion: Early administration of corticosteroids without anti-tuberculous therapy in presumed ocular tuberculosis may lead to poor visual outcome compared with patients who did not receive corticosteroids prior to presentation. Furthermore, the severity of chorioretinitis lesion in the group of patients given corticosteroid prior to ATT may account for the poor visual outcome. [ABSTRACT FROM AUTHOR]

Please cite this paper as: Para-phenylenediamine-specific lymphocyte activation test: a sensitive in vitro assay to detect para-phenylenediamine sensitization in patients with severe allergic reactions. Experimental Dermatology 2010; 19: 435–441. Patients sensitized to para-phenylenediamine (PPD) by semi-permanent tattoos increasingly develop threatening allergic reactions in response to black hair dye. The gold standard to diagnose allergic contact dermatitis is to perform epicutaneous patch tests, however, iatrogenic sensitizations and severe patch test reactions to PPD have been described, the latter especially in patients with severe allergic reactions. We examined nine patients with severe allergic reactions in response to permanent hair dyes. Patch tests using the standard concentration of 1% or 0.5% PPD resulted in severe and sometimes even bullous reactions in all patients responsive to PPD. Titration revealed that at 1% of the standard concentration (0.01% PPD), patch test sensitivity decreased and only 50% of patients responded. Consequently, we established an in vitro assay to diagnose PPD allergy. Freshly isolated peripheral blood mononuclear cells (PBMC) were cultured with titrated concentrations of PPD with or without IL-2 supplementation, and cell proliferation was determined by [3H]-thymidine incorporation. Lymphocyte activation test (LAT ) detected PBMC cell proliferation specific to PPD, with at least 3.5-fold increase in [3H]-thymidine uptake in all PPD allergic patients. Most importantly, PPD –LAT without IL-2 supplementation remained negative in three out of eight PPD allergic patients. Thus, PPD-LAT with IL-2 supplementation demonstrated a sensitivity of 100%, remained unresponsive in controls not sensitized to PPD, and in one patient sensitive to other p-amino compounds. These data demonstrate that LAT with PPD can be used to detect PPD sensitization as a possible alternative to patch testing at least in patients with severe allergic reactions to PPD. [ABSTRACT FROM AUTHOR]

Abstract: Yellow lupin diphosphonucleotide phosphatase/phosphodiesterase (PPD1) represents a novel group of enzymes. Here we report that it possesses one iron atom and one manganese atom (1:1 molar ratio) per subunit. The enzyme exhibits visible absorption maximum at ∼530nm. Prolonged oxidation of PPD1 leads to loss of the charge-transfer band and catalytic activity, whereas after reduction PPD1 remains active. Replacement of conserved amino-acid residues coordinating metals results in the loss of enzymatic activity. Despite low amino-acid sequence homology of PPD1 to well-characterized ∼55-kDa purple acid phosphatases, their overall fold, topology of active center and metal content are highly similar. [Copyright &y& Elsevier]

Many women and men now dye their hair. p-Phenylenediamine (PPD) is a frequent and important component of permanent hair dye products; exposure to it may cause allergic contact sensitization, acute dermatitis, and severe facial oedema. To increase our understanding of PPD allergy, we reviewed published literature containing PPD patch test data from dermatitis patients and individuals in the general population. This was performed to estimate the median prevalence and the weighted average of PPD sensitization and thereby assess the burden of PPD-containing hair care products on health. Literature was examined using PubMed–MEDLINE, Biosis, and Science Citation Index. The median prevalence among dermatitis patients was 4.3% in Asia, 4% in Europe, and 6.2% in North America. A widespread increase in the prevalence of PPD sensitization was observed among Asian dermatitis patients. In Europe, a decrease in the 1970s was replaced by a plateau with steady, high prevalences ranging between 2% and 6%. The prevalence remained high in North America, although a decreasing tendency was observed. Contact allergy to PPD is an important health issue for both women and men. More stringent regulation and enforcement are required as public health measures to reduce the burden of disease that exposure to PPD has brought to populations. [ABSTRACT FROM AUTHOR]

Contact allergy to hair dye ingredients, especially precursors and couplers, is a well-known entity among consumers having hair colouring done at home or at a hairdresser. The aim of the present investigation was to estimate consumer exposure to some selected precursors ( p-phenylenediamine, toluene-2,5-diamine) and couplers (3-aminophenol, 4-aminophenol, resorcinol) of oxidative hair dyes during and after hair dyeing. Concentrations of unconsumed precursors and couplers in 8 hair dye formulations for non-professional use were investigated, under the conditions reflecting hair dyeing. Oxidative hair dye formation in the absence of hair was investigated using 6 products, and 2 products were used for experimental hair dyeing. In both presence and absence of hair, significant amounts of unconsumed precursors and couplers remained in the hair dye formulations after final colour development. Thus, up to 1.1% p-phenylenediamine (PPD), 0.04% toluene-2,5-diamine, 0.02% 3-aminophenol and 0.02% resorcinol were found in the hair dye formulation after the required colour was developed. The consumers are thus exposed to precursors and couplers of oxidative hair dyes, both during and after hair dyeing, when the hair is washed. Furthermore, the consumers are also expected to be exposed to intermediates of oxidative hair dyes. The allergenic potential of oxidative hair dyes as well as the intermediates of these remains unknown. [ABSTRACT FROM AUTHOR]

The elicitation response in allergic contact dermatitis for the hair dye substance p-phenylenediamine (PPD) is dose dependent, but threshold concentrations have not previously been investigated. 15 PPD-sensitive patients participated in a serial dilution 48-hr patch test with PPD using 8 concentrations of PPD ranging from 1 to 10 000 on the upper back. Petrolatum was applied as control. Three concentrations (50, 100 and 500 p.p.m. PPD) were also applied to the retroauricular area and on the lateral aspects of the upper arms. 14 of the 15 participants reacted to one or more of the test samples. The threshold value for 10% of the tested persons (ED10) based on + or stronger reactions for PPD on the back was 38 p.p.m. (CI: 4.3–100). There were no statistically significant differences in the sensitivity of the three anatomical regions. The upper back is a suitable region for patch testing patients with hair dye dermatitis. [ABSTRACT FROM AUTHOR]

Allergic contact dermatitis following the use of hair dyes is well known. Many chemicals are used in hair dyes and it is unlikely that all cases of hair dye allergy can be diagnosed by means of patch testing withp-phenylenediamine (PPD). The objectives of this study are to identify all hair dye substances registered in Europe and to provide their tonnage data. The sensitization potential of each substance was then estimated by using a quantitative structure–activity relationship (QSAR) model and the substances were ranked according to their predicted potency. A cluster analysis was performed in order to help select a number of chemically diverse hair dye substances that could be used in subsequent clinical work. Various information sources, including the Inventory of Cosmetics Ingredients, new regulations on cosmetics, data on total use and ChemId (the Chemical Search Input website provided by the National Library of Medicine), were used in order to identify the names and structures of the hair dyes. A QSAR model, developed with the help of experimental local lymph node assay data and topological sub-structural molecular descriptors (TOPS-MODE), was used in order to predict the likely sensitization potential. Predictions for sensitization potential were made for the 229 substances that could be identified by means of a chemical structure, the majority of these hair dyes (75%) being predicted to be strong/moderate sensitizers. Only 22% were predicted to be weak sensitizers and 3% were predicted to be extremely weak or non-sensitizing. Eight of the most widely used hair dye substances were predicted to be strong/moderate sensitizers, including PPD– which is the most commonly used hair dye allergy marker in patch testing. A cluster analysis by using TOPS-MODE descriptors as inputs helped us group the hair dye substances according to their chemical similarity. This would facilitate the selection of potential substances for clinical patch testing. A patch-test series with potent, frequently used, substances representing various chemical clusters is suggested. This may prove useful in diagnosing PPD-negative patients with symptoms of hair dye allergy and would provide some clinical validation of the QSAR predictions. [ABSTRACT FROM AUTHOR]

Describes 18 cases of contact dermatitis from textile and dye allergens. Patch-testing of the patients; Reaction to at least one allergen in the dyes and chemical series; Dye with the highest frequency; Number of positive patch test reactions to the allergens in the dyes and textile chemicals series.

Intralesional immunotherapy with purified protein derivative (PPD) is an effective and tolerable therapeutic modality for the treatment of common warts. However, the complete clearance rates are still unsatisfactory. We thought to evaluate the efficacy and safety of adding low dose isotretinoin to intralesional PPD versus PPD monotherapy for viral warts. The study included two groups: Group (A) was treated by intralesional PPD at 2-week intervals until complete clearance or for a maximum of six sessions in addition to an oral placebo. Group (B): was treated with both intralesional PPD and low dose isotretinoin for a 3-month course. There was no statistically significant difference between both groups regarding the therapeutic response. In common warts, the low dose of isotretinoin did not add a true therapeutic value in the studied groups. Perhaps higher doses of isotretinoin could provide a better response, which warrants further investigation., (© 2022 Wiley Periodicals LLC.)

Different modalities are used for treatment of common warts, but none of them had been proved the best in achieving complete cure. We aim to compare the effect of cryotherapy, intralesional injection of tuberculin purified protein derivative (PPD) and cryotherapy combined with intralesional injection of tuberculin PPD in the treatment of multiple common warts. This study is a randomized clinical trial in which the patients were randomly divided into three groups; group (A) included 25 patients subjected to cryotherapy, group (B) included 25 patients subjected to intralesional injection of tuberculin PPD and group (C) included 25 patients subjected to cryotherapy plus intralesional injection of tuberculin PPD. All the three groups showed a significant clinical improvement (p < 0.001) with statistically significant difference between cryotherapy group (A) and intralesional injection of tuberculin PPD group (B) (p < 0.001) and between cryotherapy group (A) and cryotherapy plus intralesional injection of tuberculin PPD group (C) (p < 0.001). However, there was no statistically significant difference between both intralesional injection of tuberculin PPD group alone (B) and cryotherapy plus intralesional injection of tuberculin PPD group (C) (p = 0.213). In Conclusion the cryotherapy combined with intralesional injection of PPD and intralesional injection of PPD alone are better than cryotherapy alone in treatment of multiple common warts. However, better response could be reached in combination of both cryotherapy and intralesional PPD with less number of sessions., (© 2022 Wiley Periodicals LLC.)

p-phenylenediamine derivatives are widely used in industry and in cosmetics, and several of them are well-known sensitizers. One group of allergenic p-phenylenediamine derivatives are used as colour film developers. Cross-reactivity between the colour film developers has been reported. In this paper, an occupational facial dermatitis due to colour film developers is described. The patient reacted to colour film developers (CD-1, CD-2, CD-3. and CD-4), but not to other p-phenylenediamine derivatives tested. He also showed allergic reactions to Disperse Blue 106 and Disperse Blue 124 and to Disperse Red 17, but not to Disperse Orange 3. The activation of the colour him developers by oxidation at physiological pH was analysed with chemical methods, and the mechanism responsible tar the concomitant reactivities to the colour film developers and the disperse dyes at a molecular level is discussed. [ABSTRACT FROM AUTHOR]

The passive haemagglutination, enzyme-linked immunosorbent assay and indirect fluorescent antibody tests were applied to study the non-specific reactions in experimentally infected guinea pigs and tuberculin positive bovines. These cross-reactions were greatly decreased after absorption of either sera with avian PPD or bovine PPD antigen with anti-avian PPD serum. The use of both absorbed sera and antigen raised the specificity of PHA and ELISA to 100 %. The use of absorbed sera rendered the IFA specific in 95 %. The absorption has reduced the sensitivity of ELISA, IFA and PHA by 14, 27 and 29 %, respectively. Zusammenfassung Untersuchungen zur Wirksamkeit von absorbiertem bovinen PPD bei der Tuberkulinreaktion und serologischen Verfahren Passive Haemagglutination (PHA), Enzyme-linked immunosorbent assay (ELISA) und indirekte Fluoreszenzantikörpertechnik (IFA) wurden zur Untersuchung unspezifischer Reaktionen bei experimentell mit Mykobakterien infizierten Meerschweinchen und Tuberkulin-positiv reagierenden Rindern eingesetzt. Zum großen Teil wurden Kreuzreaktionen entweder durch Absorption der Seren mit aviärem PPD oder durch Absorption von bovinem PPD mit antiaviärem PPD-Serum eliminiert. Der gleichzeitige Einsatz von absorbiertem Serum als auch absorbiertem Antigen erhöhte die Spezifität von PHA und ELISA auf 100 %. Durch die Anwendung absorbierter Seren wurde die Spezifität der IFA auf 95 % gesteigert. Die Sensitivität von ELISA, IFA und PHA wurde durch die Absorption um jeweils 14, 27 und 29 % reduziert. [ABSTRACT FROM AUTHOR]

The article presents information on a case of allergic contact dermatitis, in which a 34-year-old woman developed severe and persistent blepharoconjunctivitis and centrofacial oedema, after dyeing her eyelashes. She had used a permanent black eyelash dye, containing p-Phenylenediamine (PPD). Despite oral treatment with prednisone, her dermatitis kept progressing, and patch tests with extended European baseline series showed positive reactions to PPD.

Temporary henna tattoos have become increasingly popular as a safe alternative to permanent tattoos among American and European children and teenagers during the summer holidays. Currently, temporary henna tattoos contain not only henna, but also other additives such as para-phemylenediamine (PPD), which is considered to be the chemical agent that most frequently causes skin reactions associated with the use of commercial black henna. In this report, we describe an 11-year-old boy who applied a temporary black henna tattoo on his right arm during the summer holidays in Greece and developed a severe contact dermatitis at the tattoo site with residual hypopigmentation. He had no previous history of contact dermatitis, however he did suffer from seasonal allergic rhinitis and atopic dermatitis. Patch testing revealed a strong reaction to PPD, a substance commonly contained in temporary henna tattoo preparations. Conclusion: Henna tattoos are an increasing problem worldwide since they carry an increased risk of severe skin reactions; therefore we suggest that the use of temporary henna tattoos in children be discouraged. [ABSTRACT FROM AUTHOR]

While the frequency of patch test reactivity to many cosmetic allergens has decreased over the last 20 years, we have previously shown that in our clinic, the patch test reactivity to p-phenylenediamine (PPD) has remained stubbornly high between 2.5% and 4.2% in the years when patch testing was performed with 1% PPD. Further retrospective analysis of the PPD patch test frequency over the last 6 years shows an increasing rate of PPD patch test frequency, showing an upward linear trend. This increasing trend cannot be fully explained by any increase in patch testing of Southern Asian patients or of sensitization caused by PPD exposure from ‘temporary henna tattoos’. An alternative explanation may be the increasing use of permanent hair dyes. [ABSTRACT FROM AUTHOR]

Para-phenylenediamine (PPD) and para-aminoazobenzene are strong sensitizers. By the patch test procedure, the patient may be sensitized to these agents. Combined testing of para-compounds may increase the risk of active sensitization. We studied the % of positive patch test reactions and their relevance. In order to assess the risk of active sensitization, we compared the % of relevant reactions of both early (2/3 days) and late (7 days) reactions. We also compared the percentage of positive patch test reactions to PPD and their relevance if simultaneously tested with para-aminoazobenzene. We studied the patch test reactions to PPD in the routine series in 2058 patients. In a group of 678 patients we tested PPD and para-aminoazobenzene simultaneously. 4.3% and 3.1% of the patients reacted to PPD, respectively, with and without simultaneous testing with para-aminoazobenzene. We estimated the reactions as relevant in 21.1% and 39.7%, respectively, with and without simultaneous testing with para-aminoazobenzene. We considered none of the late reactions as relevant. We found a high proportion of relevant patch test reactions to PPD, but sensitization to PPD by the patch test procedure is a risk. We state that routine series should not contain PPD. The high number of irrelevant late positive reactions strongly suggests active sensitization. Moreover, PPD is not a ubiquitous allergen and can be tested on a non-routine basis if industrial exposure to para-compounds is suspected or if a specific localization (e.g., head or feet) prompts the testing of PPD. Testing PPD combined with para-aminoazobenzene does lead to a slight increase in positive reactions to PPD (p<0.25) and to an increase in irrelevant reactions (p<0.10). [ABSTRACT FROM AUTHOR]

Intralesional immunotherapy by different antigens has shown promising efficacy and safety in the treatment of warts. However, the use of these antigens for the treatment of plane warts has been investigated in two studies only. To evaluate the efficacy and safety of three antigens; Measles Mumps, Rubella vaccine (MMR), Candida antigen, and purified protein derivative (PPD) in the treatment of multiple plane warts. The study included 120 patients who were randomly assigned to three groups, 40 patients in each group. Each agent was injected intralesionally at a dose of 0.1 mL into the largest wart at 2-week intervals until complete clearance or for a maximum of five sessions. Complete clearance of warts was observed in 55% of the PPD group, in 70% of the Candida antigen group, and in 62.5% of the MMR group. No statistically significant difference in the therapeutic response was found between the three groups. Intralesional antigen immunotherapy seems to be a promising well-tolerated and effective therapeutic option for the treatment of multiple plane warts, with relatively higher efficacy of Candida antigen., (© 2020 Wiley Periodicals LLC.)

The article presents case studies for several patients associated with contact dermatitis as an allergic reaction through eyelash tinting. Topics include utilization of p-phenylenediamine (PPD) as sensitizer for an eyelash tinting that leads to contact allergy; concerns over development of several abnormalities in eyes with eyelash tinting conditions such as blepharo-conjunctivitis; and adoption of patch testing approaches under the British Society for Cutaneous Allergy (BSCA) guidelines.

The article presents a study "Allergic contact dermatitis to the hair dye 6-methoxy-2-methylamino-3-aminopyridine HCl (INCIHC Blue no.7) without cross-sensitivity to PPD". It presents a case of a woman who had coloured her hair with oxidative hair dyes and she developed severe edema around her eyes and exudation from the scalp and ears. It has revealed that the patient was positive to HC blue no. 7 and negative to p-Phenylenediamine (PPD).

The article presents a case study of a 54-year-old woman who developed erythema, oedema, and scaling of the face, neck, and arms after she had her hair dyed in a hairdressing salon with four different tones of Wella hair dyes. The patient had never been patch tested before, and was not aware of the harm of other hair dyes. The patient was patch tested using standard patch tests and standard prick tests including latex.

The article focuses on a case study involving a 36-year-old woman with allergic contact dermatitis produced by toluene-2,5-diamine contained in a cosmetic product. Results showed that toluene-2,5-diamine is a major allergen causing skin inflammation. The study stresses that patients with allergic response to pyrocatechol should avoid hair dyeing products with toluene-2,5-diamine since they cross-react with each other.

Para-phenylenediamine (PPD), a constituent of permanent hair dyes, may cause contact allergy in exposed individuals. It has previously been questioned whether a patch testing with PPD in population-based epidemiological studies is entirely safe. The Glostrup allergy studies patch tested the same cohort twice. In 1990, 567 persons were patch-tested and only one person had a (+) positive reaction to PPD. In 1998, 540 persons were re-invited to a new patch test and 365 (participation rate 68%) were re-tested. There were no positive reactions to PPD. These studies indicate that patch testing with PPD in individuals with no previous positive reactions to PPD or with only one previous positive reaction does not cause active sensitization and can be performed with minimal risk. [ABSTRACT FROM AUTHOR]

The article presents a medical case of a 40-year old man who had a henna tattoo painted on his left upper arm and several hours later, a painful, itchy bullous eruptions appearing at the application site. He developed a positive reaction to paraphenylendiamine which contained in the prescribed oral drug.

Temporary‘black henna’ tattoos are an increasingly popular body decoration with a growing incidence of associated adverse events. We report the case of a 14 year old girl presenting with an acute allergic contact dermatitis to hair dyes. Some years previously she had a‘black henna’ tattoo with prior application of a tacky transfer to the skin to outline the design followed some days later by an acute localised blistering reaction. Patch testing to an extended British Contact Dermatitis Society standard series showed relevant positive reactions to paraphenlyenediamine(PPD) and thiuram mix, as well as to several of the azo disperse dyes. We went on to perform prick testing to natural rubber latex(NRL), showing a positive reaction to the commercial HEP 100 concentration. We propose that through the initial acute reaction caused by PPD in the‘black henna’ our patient was not only sensitized to PPD, but also to thiuram and natural rubber latex which may have been present in the tacky transfer applied prior to‘tattooing.’ We would add that temporary‘black henna’ tattoos may have more important consequences than previously thought on patients’ future health by sensitization to NRL. [ABSTRACT FROM AUTHOR]

Reports on allergic contact dermatitis (ACD) in 191 consecutively patch tested children in Great Britain. Prevalence of ACD; Identification of allergens particularly relevant to childhood ACD.

The article presents a case study of phenylenediamine base substance (PPD), the most common active ingredient in hair dyeswhich may cause connubial dermatitis. The presented case highlights the importance of a detailed contact history and specific enquiry about substances that may cause connubial dermatitis when confronted with unusual patch test.

The article reports on black henna tattoo's complications. A case of a 9-year old boy who had a henna tattoo painted on his body suffered and allergic reaction to the application site and eventually disseminated to other parts of his body. Months later upon dyeing his hair black, he developed papulovesicular eruptions at the hairline accompanied by pruritus. Patch test showed positive reactions to lawsone, benzocaine, paraphenylendiamine, and propyl-diphenylenediamine.

Focuses on the performance of patch testing for para-phenylenediamine (PPD) in patients with reaction to henna tattoos. Rate of patients which test positive to PPD; Risk involve which such application; Need on not to routinely patch test the patients sensitized by henna tattoos.

Reports on the repatching of patients with long-term contact dermatitis in Poland. Signs and symptoms; Diagnostic procedures; Treatment regimen; Outcome.

Summary Background Several epidemiological and experimental studies have demonstrated that exposure to pathogens such as those from the genus Mycobacterium leads to the suppression of allergic sensitization and inflammation. However, little is known as to whether pathogen-derived soluble antigens have the potential to modulate the pathogenesis of allergic rhinitis. Objective We sought to determine whether application of purified protein derivative (PPD) from Mycobacterium tuberculosis can suppress the initiation and/or exacerbation of allergic rhinitis using a recently developed murine model. Methods First, we investigated whether a single intranasal application of PPD could elicit cytokine production in the nose by RT-PCR. BALB/c mice were repeatedly sensitized with Schistosoma mansoni egg antigen (SEA) intranasally without an adjuvant. PPD was applied through different routes either before or after sensitization. The production of SEA-specific antibodies, nasal eosinophilia and cytokines by nasal lymphocytes was compared among mice that had or had not received PPD treatment. Results IFN-γ, but not IL-4, was detected in the nasal tissue 12 to 48 h after a single intranasal application of 10 µg PPD. Repeated intranasal application of PPD prior to and during sensitization with SEA significantly inhibited the production of both SEA-specific IgE/IgG1 and nasal eosinophilia. Moreover, it partially inhibited the production of IL-4 by nasal lymphocytes in response to SEA. Conversely, this treatment led to a significant increase in IFN-γ production. On the other hand, PPD applied through the footpad had no effect over the same period. Repeated intranasal application of PPD after sensitization with SEA had no exacerbative effect on allergic inflammation. Conclusion These results indicate that the local application of PPD, and the subsequent induction of IFN-γ, inhibits the initiation, but not the exacerbation, of allergic rhinitis in mice. This... [ABSTRACT FROM AUTHOR]