Search

Abstract Background and Aims Vitamins are bioactive compounds naturally found in many different types of food and required by the human body for many biological functions and enzymatic activities. Due to their antioxidant properties, certain vitamin derivatives have been synthesized for inclusion in many cosmetics, thus leading to an increasing incidence of allergic contact dermatitis (ACD) cases. Therefore, the present review may be helpful to provide an insight into the sensitizing role of at least certain vitamins and may also offer possible patch test alternatives for definitive diagnosis. Methods This study was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta‐Analyses (PRISMA) guidelines. Literature search regarding ACD cases to vitamins was performed using the Medline, PubMed, Scopus, EMBASE, and Google Scholar databases from January 1940 up to June 2021. Results A total of 4494 articles matched the keywords used for the researched. Records removed before screening included 15 duplicate articles and 3429 not eligible articles (e.g., not written in English, studies on animals, not relevant to the topic). A total of 1050 articles underwent the screening phase and 258 were therefore excluded as they were not primary studies. Subsequentially, 792 articles were considered eligible for the review and 688 of them were finally excluded as they did not report the outcome of interest. Therefore, 104 articles were definitely included in the present review. Conclusion ACD to vitamins is still probably an underestimated issue in cosmetology, as many vitamins are considered “natural” and therefore “safe” ingredients. On the contrary, according to current literature, almost all vitamins contained in topical products are able to induce allergic reactions, with the exception of vitamin B2 and vitamin B9. Patch tests are not standardized, thus leading to difficulties in diagnosis.

Background: An aqueous antiseptic containing "chlorhexidine digluconate/benzalkonium chloride/benzyl alcohol" (CBB) is widely used in France. The only previous documented study dealing with allergic contact dermatitis (ACD) to this antiseptic is one small case series in children. The French Vigilance Network for Dermatology and Allergy (REVIDAL-GERDA) has collected many cases in the last few years., Objectives: To evaluate the clinical and sensitization profiles of patients diagnosed with ACD to CBB., Methods: We performed a retrospective study of patients with contact dermatitis to CBB and positive tests to CBB and/or at least one of its components. All patients had to be tested with all components of CBB., Results: A total of 102 patients (71 adults and 31 children) were included. The lesions were extensive in 63% of patients and 55% had delayed time to diagnosis. CBB patch tests were positive in 93.8% of cases. The allergen was identified in 97% of patients, mainly benzyl alcohol in adults (81.7%) and chlorhexidine digluconate in children (54.8%). About 32.4% of the patients were sensitized to several components., Conclusion: CBB is a cause of ACD at all ages. The components of the antiseptic should be tested. The sensitization profile seems to be different between adults and children., (© 2022 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Skin tests, including patch tests (PTs), prick tests, and intradermal tests (IDTs), are useful in identifying the culprits of cutaneous adverse drug reactions (CADRs), and determining safer, alternative drugs. PTs have a low sensitivity but are valuable in investigating maculopapular exanthema (MPE), as well as severe CADR, including toxic epidermal necrolysis (TEN), Stevens-Johnson syndrome (SJS), and in particular, acute generalized exanthematous pustulosis (AGEP), and drug reaction with eosinophilia and systemic symptoms (DRESS). To ensure their specificity, at least 10 control tests should be performed. Prick tests are mainly used in the evaluation of immediate-type hypersensitivity and can be performed with all drugs, except opiates. IDTs can be used to explore immediate and delayed-type hypersensitivity, if an injectable form of the drug exists. Except for SJS/TEN, IDTs should be performed by injecting 0.02 mL of the drug. We here provide a practical, up-to-date review on the use of these skin tests in the work-up of CADRs. Numerous negative controls for drug PTs, as well as criteria for the immediate and delayed positivity of prick tests and IDT, are included. It should be emphasized that a negative result never excludes the potential responsibility of a drug in a CADR., (© 2022 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Allergic contact dermatitis to gloves is mostly induced by rubber accelerators. The European baseline series (EBS) appears insufficient to detect glove allergy. Since 2017, it is recommended to use the European rubber series (ERS) and to test the patients' own gloves., Objectives: To investigate the clinical profile of glove-wearing patients with hand eczema (HE) and to evaluate their sensitisation profile to glove allergens and the value of testing the patients' own gloves., Methods: We conducted a French multicentre study of patients evaluated for HE between 2018 and 2020 and tested with the EBS, the ERS and their own gloves in patch tests and semi-open (SO) tests., Results: A total of 279 patients were included; 32.6% of patients had positive tests to their own gloves or to glove allergens. Almost 45% of the sensitisations to glove allergens were detected only by the ERS. Among the patients tested both in patch tests and SO tests with their own gloves with positive results, 28% had positive SO tests only. Polyvinylchloride (PVC) gloves were positive in four patients., Conclusion: Our series confirms the need to test the ERS. All the patients' gloves must also be tested including PVC gloves. SO tests with gloves are useful as a complement to patch tests., (© 2023 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: To analyse the clinical characteristics and sensitivity of an essential oil patch test series (EOS) in patients sensitized to their own essential oils (EOs)., Method: We analysed the clinical data and patch test results obtained with the European baseline series (BSE) and an EOS, as well as the mode of use of EOs, through a questionnaire included in the patient file., Results: The study included 42 patients (79% women, average age 50 years) with allergic contact dermatitis (ACD), 8 patients required hospitalization. All patients were sensitized to the EO they used, primarily lavender (Lavandula augustifolia, 8000-28-0), tea tree (Melaleuca alternifolia leaf oil, 68647-73-4), ravintsara (Cinnamomum camphora oil, 92201-50-8), and 2 cases were attributed to helichrysum (helichrysum italicum flower absolute, 90045-56-0). 71% had positive patch tests to fragrance mix I or II, 9 only to the EOS and 4 only with their personal EO. Interestingly, 40% of patients did not spontaneously mention the use of EOs, and only 33% received advice on their use at the time of purchase., Conclusion: Patch tests with the BSE, limonene and linalool HP, and oxidized tea tree oil is sufficient to detect most EO-sensitized patients. The most important is to test the patient's own used EOs., (© 2023 The Authors. Contact Dermatitis published by John Wiley & Sons Ltd.)

Lymphocyte multiplication can be induced in vitro by mitogens or specific antigens, and is usually measured using isotopic methods involving tritiated thymidine. Cellular proliferation can also be analyzed by flow cytometry techniques based on cell cycle analysis through the measurement of DNA content. We applied this method to lymphocytes from 113 individuals, to evaluate lymphocyte proliferation after stimulation in vitro by a mitogen (phytohaemagglutinin, PHA) or a recall antigen (tetanus toxoid), using a kinetic approach with four points sequential measurements of the S and G2 phases over six days of culture. The proportion of cells in S phase after PHA stimulation was significantly higher than in controls overall and as early as on day three of the culture. Activation with a recall antigen significantly induced increasing S phase cell proportions up to day six. These data suggest that flow cytometric assessment of the S phase could be a useful alternative to isotopic methods measuring lymphocyte reactivity in vitro.

Background and Objectives: The repeated open application test (ROAT) is an adjuvant investigation measure to patch testing in the diagnosis of allergic contact dermatitis. ESCD recommends a 15 days duration but its overall duration varies according to publications and patients hardly adhere to prolonged ROAT duration beyond 1 week., Materials and Methods: The Dermatology and Allergy Group of the French Society of Dermatology performed a prospective study with the aim of determining the best duration for the ROAT., Results: A total of 328 ROAT results were collected for topical products, including cosmetics (60%) and topical medications (31.1%). Fifty-nine (18%) ROATs were positive, and 16 (5%) were doubtful. All the positive ROATs occurred within 10 days, with a median time to positivity of 3 days., Conclusion: According to our results, a minimum duration of 10 days is necessary to achieve a positive ROAT to a topical product., (© 2022 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Patch tests (PTs) are recommended to identify the culprit drug in non-immediate cutaneous adverse drug reactions (NICADRs). We recently reported that, in patients with NICADRs, a unique reading of PTs at day (D)2 compared with an additional second late reading at D4 missed almost half (45.3%) of the positive PTs., Objectives: To assess the change in sensitivity of the PT reading on D4 compared with the reading on D3., Methods: We performed a retrospective (July 2020-June 2023) monocentric study of patients who had PTs with two readings for a NICADR. We compared reading on D3 and the second reading on D4 for the suspected drug (primary outcome) and for the related drugs tested simultaneously (secondary outcome)., Results: During the study period, 249 patients underwent patch testing with D3 and D4 readings. Regarding the primary outcome, the first reading at D3 was positive for 13.7% of patients, and the reading at D4 for 24.9% of patients (p < 0.0001). Regarding the secondary outcome, only 9.6% of patients had all their positive PT at D3 compared with 24.9% of patients at D4 (p < 0.0001). Considering the evaluated drug classes, no statistical difference was observed. However, we highlight that D3 reading detected all positive carbamazepine PTs (n = 3) while positive clindamycin PTs (n = 4) were identified only with the help of the second reading on D4., Conclusion: This study showed that, an additional D4 reading compared with a single D3 reading enhanced the sensitivity of PTs to identify culprit drugs and related. Further studies should replicate these findings and evaluate the medico-economic balance and safety of a single reading of PTs on D4., (© 2024 The Author(s). Contact Dermatitis published by John Wiley & Sons Ltd.)

Background: Eyelids are frequent sites of contact dermatitis. No prospective study focused on eyelid allergic contact dermatitis (EACD) has yet been published, and this topic has never been studied in French patients., Objectives: To prospectively evaluate the usefulness of an eyelid series in French patients patch tested because of EACD, and to describe these patients., Methods: We prospectively analysed standardized data for all patients referred to our departments between September 2014 and August 2016 for patch testing for suspected EACD as the main reason. All patients were patch tested with an eyelid series, the European baseline series (EBS), the French additional series, and their personal products. Patch testing with additional series and repeated open application tests (ROATs) or open tests were performed if necessary. A standardized assessment of the relevance was used, and the analysis of the results was focused on patients having positive test results with a current certain relevance., Results: Two-hundred and sixty-four patients (238 women and 26 men) were included. Three-hundred and twenty-two tests gave positive results in 167 patients, 84 of whom had currently relevant reactions: 56 had currently relevant positive test reactions to the EBS, 16 had currently relevant positive test reactions to their personal products, 8 had currently relevant positive test reactions to the French additional series, and 4 had currently relevant positive test reactions to the eyelid series. Sixty-seven per cent of all relevant cases were related to cosmetic products. The most frequent allergens with current relevance were methylisothiazolinone (10.2%), fragrance mix I (3%), nickel (2.7%), hydroxyperoxides of linalool (2.7%) and limonene (2.3%), and Myroxylon pereirae (2.3%). Current atopic dermatitis was found in 9.5% of patients. The duration of dermatitis was shorter (23.2 vs 34.2 months; P = .035) in patients with currently relevant test reactions. The percentage of currently relevant tests remained the same when atopic patients or dermatitis localized only on the eyelids were taken into account., Conclusion: In French patients, testing for EACD with the extended baseline series and personal products, also including ROATs and use tests, appears to be adequate, considering the currently relevant positive test reactions. The regular addition of an eyelid series does not seem to be necessary., (© 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Airborne allergic contact dermatitis caused by paints containing isothiazolinones has been recognized as a health hazard., Objectives: To collect epidemiological, clinical and patch test data on airborne allergic contact dermatitis caused by isothiazolinone-containing paints in France and Belgium., Methods: A descriptive, retrospective study was initiated by the Dermatology and Allergy Group of the French Society of Dermatology, including methylchloroisothiazolinone (MCI)/methylisothiazolinone (MI)- and/or MI-sensitized patients who developed airborne allergic contact dermatitis following exposure to isothiazolinone-containing paint., Results: Forty-four cases were identified, with mostly non-occupational exposure (79.5%). Of the patients, 22.5% of also had mucosal symptoms. In several cases, the dermatitis required systemic corticosteroids (27.3%), hospitalization (9.1%), and/or sick leave (20.5%). A median delay of 5.5 weeks was necessary to enable patients to enter a freshly painted room without a flare-up of their dermatitis. Approximately one-fifth of the patients knew that they were allergic to MI and/or MCI/MI before the exposure to paints occurred., Conclusion: Our series confirms that airborne allergic contact dermatitis caused by paints containing isothiazolinones is not rare, and may be severe and long-lasting. Better regulation of isothiazolinone concentrations in paints, and their adequate labelling, is urgently needed., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Drug hypersensitivity reactions (DHRs) affect an unknown proportion of the general population, and are an important public health problem due to their potential to cause life-threatening anaphylaxis and rare severe cutaneous allergic reactions. DHR evaluations are frequently needed in both ambulatory and hospital settings and have a complex diagnosis that requires a detailed clinical history and other tests that may include in vitro tests and in vivo procedures such as skin tests and drug provocation tests. Although over the years both European and U.S. experts have published statements on general procedures for evaluating DHRs, a substantial discordance in their daily management exists. In this review, we highlight both the differences and the similarities between the European and U.S., Perspectives: While a general consensus exists on the importance of skin tests for evaluating DHRs, concordance between Americans and Europeans exists solely regarding their use in immediate reactions and the fact that a confirmation of a presumptive diagnosis by drug provocation tests is often the only reliable way to establish a diagnosis. Finally, great heterogeneity exists in the application of in vitro tests, which require further study to be well validated.

2-Hydroxyethyl methacrylate (HEMA) has been increasingly recognised as a contact allergen and was added to the European baseline series in 2019. In this article (2 parts), the results of an extensive literature review of the clinical aspects of contact allergy/allergic contact dermatitis to HEMA are presented. In part 1, the epidemiology of HEMA contact allergy is discussed and detailed information on published case series and case reports presented. HEMA is an important cause of contact allergy/allergic contact dermatitis in North America and Europe with recent prevalences of >3% in the USA + Canada and 1.5%-3.7% in Europe. Currently, most cases are caused by nail cosmetics, both in consumers and professional nail stylists. In our literature review, we have found 24 studies presenting case series of patients with allergic contact dermatitis attributed to HEMA and 168 case reports. However, the presence of HEMA in the products causing ACD was established in only a minority. Part 2 will discuss cross- and co-sensitisation, and other skin reactions to HEMA, will assess whether HEMA is the most frequent (meth)acrylate allergen and how sensitive HEMA as a screening agent is, investigate the presence of HEMA in commercial products and provide practical information on patch testing procedures., (© 2023 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Furazolidone is a nitrofuran antimicrobial agent used in the treatment of bacterial and protozoal infections. Hypersensitivity to furazolidone is rarely reported and only eight cases have been documented in English since 1967., Objectives: To report a 24-year-old man who developed exanthematous drug eruptions in general and swelling sensation of the hands after first dose of oral administration of medicines for Helicobacter pylori infection 7 h later, who was finally confirmed with delayed-type IV allergic reaction to furazolidone by provocation tests. And to review the existing literature., Methods: Thorough clinical examination, prick, intradermal, and patch tests, drug provocation tests were performed in the patient., Results: Skin tests of all used drugs were negative. Drug provocation tests to furazolidone resulted to be positive., Conclusions: Clinicians should be aware that furazolidone may induce delayed-type allergic reactions; diagnostic approaches should be taken to identify the responsible drug when multiple medications were used concurrently., (© 2023 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Drug reaction with eosinophilia and systemic symptoms (DRESS) is a severe adverse drug reaction. It is uncommon in the paediatric population and can be difficult to diagnose as its initial symptoms may mimic a viral infection., Objective: To analyse the features of paediatric DRESS and to evaluate the interest of skin tests in identifying the causative drugs., Methods: It is a retrospective analysis (2004-2021) of DRESS cases diagnosed in paediatric patients. The DRESS diagnosis was defined using the RegiSCAR scoring. The skin tests were performed according to the ENDA recommendations., Results: We included 19 cases of DRESS occurred in 18 patients. Common clinical symptoms were exanthema and fever in 94.7% of cases each. The most commonly affected organ was the liver (84.2%). Among the implicated drugs, 16 were tested and skin tests were positive in 75%. To assess cross-reactivity and co-sensitization, skin tests with related and/or co-administered drugs were performed in eight patients. Among them, only one child had positive results., Conclusion: Early diagnosis of DRESS and discontinuation of the incriminated drug might reduce the incidence of mortality in the paediatric population. Skin tests could be a safe and useful tool to identify the causative drug and assess cross-reactivity., (© 2023 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Modern dressings (MDs) may have a low sensitization rate, but there is a lack of prospective studies in patients with chronic leg ulcers (CLUs) to evaluate this., Objectives: To determine the rate of sensitization (contact allergy) to MDs and substances present in dressings., Patients and Methods: A prospective multicentre study was carried out in patients with CLUs at five French dermatology departments; patch tests were performed with the European baseline series and with an additional 27 individual allergens and 10 MDs., Results: Among 354 patients (226 women and 128 men) with CLUs, 59.6% had at least one positive patch test reaction to an MD and 19% had at least one sensitization to an MD. The number of positive test reactions per patient was correlated with the duration of ulcerative disease, but not with ulcer duration, the cause of the ulcer, or the presence of surrounding eczematous lesions. For 11 of 45 patients sensitized to Ialuset cream®, more detailed information could be obtained with sensitization to sodium dehydroacetate (5 cases) or Lanette SX® (3 cases)., Conclusions: Sensitization to MDs is not rare. It is absolutely necessary to label all components of MDs on their packaging and to avoid some sensitizing molecules, such as colophonium derivatives or any strong sensitizers., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Drug patch tests (DPTs) with medicaments suspected of causing an allergic reaction represent a method of diagnostic testing that is low risk; DPTs can reproduce delayed hypersensitivity to drugs, and entail only a moderate re-exposure of patients to potential offending drugs. We assessed the non-irritating concentrations of DPTs and determined the amounts of active ingredient (AI) contained in the drugs used in the tests., Objectives: The objectives were to assess the non-irritating concentration of DPTs and determine the amounts of active ingredient (AI) contained in the drugs used in the tests., Methods: From a retrospective, single-centre study of all patients investigated during a 6-year period with a drug eruption, each potentially responsible drug was tested with the commercially available preparation diluted to 30% in water, petrolatum, or alcohol. Data collection was performed with a customized computer database. For each type of DPT studied, the numbers of positive and negative test results were recorded. The amount of AI contained in the DPT (as a percentage) was then calculated after weighing of each tablet., Results: Of the 5558 DPTs studied, all were non-irritant. The average concentration of AI was 9.8%; 25% of DPTs had an AI concentration of < 2%, and 25% had an AI concentration of > 16%. The AI concentration ranged from 0.05% (digoxin) to 30% (paracetamol lyophilisate)., Conclusion: These data provide thresholds for the non-irritating concentration of AI of 68 different drugs, and thresholds for the non-irritating dilution for 82 drugs, and will help to standardize DPT methods., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: The preservative methylisothiazolinone (MI) is used in combination with methylchloroisothiazolinone (MCI), but the MCI/MI mixture has been identified as highly allergenic. MI is considered to be less allergenic, and since the mid-2000s has been widely used alone, but is now clearly identified as a contact allergen. The French Vigilance Network for Dermatology and Allergy of the Study and Research Group on Contact Dermatitis (REVIDAL-GERDA) added MI to its baseline patch testing series in 2010., Objective: To evaluate the change in the proportion of MI-positive tests in France between 2010 and 2012., Patients/materials/methods: We conducted a nationwide, multicentre, retrospective study of all MI-tested patients between 2010 and 2012., Results: Sixteen centres participated in the study (7874 patients were tested). Patch tests were performed mainly at a concentration of MI 200 ppm aq. We observed a significant increase in the proportion of MI-positive tests in 2012 and 2011 as compared with 2010 (5.6%, 3.3%, and 1.5%, respectively; p < 0.001)., Conclusions: We report a significant increase in the number of MI-positive tests. MI is confirmed to be a rapidly emerging allergen, as also observed in other European countries., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: There is a lack of prospective studies investigating contact sensitization in patients with chronic leg ulcers., Objectives: To determine the frequency of contact sensitization in patients with chronic leg ulcers using a special series of patch tests and to determine whether the number of sensitizations was correlated with the duration of the chronic leg ulcers., Patients/methods: Multicentre study carried out in patients with chronic leg ulcers; patch tests with the European baseline series and with an additional 34 individual allergens or mixes and 3 commercial products., Results: Of the 423 patients (301 women, 122 men, mean age 68.5 years) with chronic leg ulcers, 308 (73%) had at least one positive patch test with 3.65 positive patch tests per patient. The main allergens were Myroxylon pereirae (41%), fragrance mix I (26.5%), antiseptics (20%), and corticosteroids (8%). The number of positive tests per patient was not correlated with the cause of ulcer but was increased with the duration of the ulcer with a statistical difference between the group of the <1 year compared with the group >10 years duration., Conclusions: From this large prospective multicentre study, polysensitization is frequent in patients with chronic leg ulcers, increasing with the duration of the ulcer. We propose avoidance of topical antiseptics and ointments containing perfumes in patients with chronic leg ulcers and an updated patch test series for investigating these patients.

Cutaneous adverse drug reactions (CADR) during chemotherapy are not rare, but difficult to manage. Case 1, a 49-year-old man was treated with 5-fluorouracil, irinotecan, and oxaliplatin for a pancreatic tumour. He developed a generalized urticaria during his seventh course of chemotherapy. 2 months later, skin tests determined a granisetron allergy with an ondansetron cross-reaction. Substituting the anti-emetic allowed continuation of the chemotherapy. Case 2, a 44-year-old woman, having recurring breast cancer that was treated with doxorubicin, and docetaxel developed a maculo-papular rash (MPR) the day after the first chemotherapy treatment. 2 weeks later, skin tests determined a corticosteroid class A allergy. Using a class C corticosteroid, no other reaction occurred. Case 3, a 44-year-old woman, having breast cancer treated with 5-fluorouracil, cyclophosphamide, and epirubicin developed an MPR after the second chemotherapy treatment. 12 days later, skin tests showed a granisetron allergy. Using alizapride, chemotherapy was continued with no further reaction. CADR necessitate a thorough investigation, modified according to the patient's chemotherapy treatment chronology and precautions while testing the molecules. Tests are rarely carried out, however, these tests allow for continuation of effective chemotherapy once the responsible agent has been determined. The 3 cases reported underline the role of complementary treatment and the necessity to test those molecules.

We report the first case of immediate-type hypersensitivity caused by Emla cream. A 55-year-old woman, after using Emla cream, went on to develop urticaria. An open test was positive to Emla cream. Patch tests and prick tests were performed with Emla cream, the components of Emla cream (lidocaine, prilocaine and castor oil) and other local anaesthetics. The patch test with lidocaine and the prick test with Emla cream were both positive. An intradermal test and subcutaneous administration of 3 anaesthetics that had negative patch tests and prick tests were performed and well tolerated, allowing their use. In the literature, anaphylactic reactions to lidocaine injections, delayed-type hypersensitivity after lidocaine subcutaneous injections and contact dermatitis from Emla cream have all been described. This first case of contact urticaria from Emla cream was due to lidocaine and did not show any cross-reaction with other local anaesthetics.

Delayed reactions to radio-contrast media (RCM) with positive skin tests are rare. We report the study of a series of 15 patients who presented delayed reactions to RCM, with an analysis of the clinical features and the results of standardized drug skin tests. Patch tests were performed with RCM and iodized antiseptics (IAs). If negative, prick tests were performed, followed by intradermal tests (IDTs), then intravenous administration under hospital surveillance. The main clinical features were maculopapular rashes or a macular rubella-like rashes. Patch tests were positive with RCM in 2 of 15 cases and with IAs in 4 of 15 cases. All the prick tests were negative. IDTs were positive at 24 h in 8 of 15 cases. 5 of 12 patients had a non-severe relapse of the rash upon receiving an RCM despite clearly negative skin tests with the readministered RCM. Visipaque cross-reacted with Iopamiron, Iomeron, Telebrix, Omnipaque, Xenetix and Hexabrix. Omnipaque cross-reacted with Hexabrix and Iopamiron. IDTs with delayed readings are of better value than patch tests in such patients. The readministration of RCM with negative IDTs must be performed with progressive amounts under hospital surveillance. Cross-reactions between various classes of RCM are frequent. The responsible epitopes are unknown. Iodine itself could be involved.

The present study was made to determine the value of drug skin tests in patients with cutaneous adverse drug reactions (CADRs) due to a synergistin (pristinamycin) and to determine the frequency of cross-reactions between synergistins. 29 patients were referred during the onset of the CADR due to pristinamycin: 18 with maculopapular rash, 9 erythrodermas, 1 angioedema and 1 Stevens-Johnson syndrome. They all had patch tests with pristinamycin and, in most cases, with other synergistins [virginiamycin and dalfopristin-quinupristin (DQ)], prick tests (10 cases) and intradermal tests (IDT) (5 cases). Skin tests with synergistins were positive in 27 cases, patch tests with pristinamycin in 20/29 cases (69%), prick tests with pristinamycin in 3/9 cases on immediate (1 case) or on delayed (2 cases) readings, and IDT with DQ in 4/5 cases. Cross-reactions between synergistins occurred in 9/22 with virginiamycin and in 7/8 cases with DQ. Skin tests with synergistins are useful in investigating CADR due to pristinamycin. Synergistins are composed of 2 chains (1 depsipeptide and 1 macrocyclic lactone) with many structural analogies between all synergistins. According to the chemical structures and our results, it seems advisable to avoid all synergistins in patients with CADR due to pristinamycin.

Allergic contact dermatitis caused by acyclovir is rare. We report the 5th case of systemic acyclovir reaction subsequent to acyclovir contact dermatitis, with investigations made to determine an alternative antiviral treatment. A 23-year-old woman, after dermatitis while using Zovirax cream, went on to develop urticaria after oral acyclovir. Patch tests were performed with the components of Zovirax cream (acyclovir, propylene glycol and sodium lauryl sulfate) and with other antiviral drugs. Patch tests were positive to Zovirax cream, acyclovir, valacyclovir and propylene glycol. Patch and prick tests with famciclovir were negative, but its oral administration caused an itchy erythematous dermatitis on the trunk and extremities. Our patient developed a systemic acyclovir reaction subsequent to acyclovir allergic contact dermatitis, with cross-reactions to valacyclovir and famciclovir. Their common chemical structure is the 2-aminopurine nucleus. It is probably this part of the molecule that provokes both contact allergy and systemic reactions. The only antiviral drugs not having this core are foscarnet and cidofovir, and these could therefore be alternatives.

Dermatologic fungal infections are thought to occur less frequently in children than in adults. This study, performed over a 5-year period, emphasizes the interregional variability of dermatophytes that cause skin and cutaneous apprendageal diseases in children. In northeast France, two-thirds of dermatophytoses are due to zoophilic fungi, while they are most commonly caused by anthropophilic agents in the Paris region and in other countries. The clinical features of pediatric dermatophytoses vary with the age of the child: tinea capitis and tinea corporis are far more frequent before the age of 12 years. After the age of 12, even if these are still quite frequent, tinea pedis and onychomycosis become more common.

Skin testing with a suspected drug has been reported to be helpful in determining the cause of cutaneous adverse drug reactions (CADR). Many isolated reports of positive drug skin tests are published, but without detailed information concerning the clinical features of the CADR and the method used in performing drug skin tests, such data are not very informative. A working party of the European Society of Contact Dermatitis (ESCD) for the study of skin testing in investigating cutaneous adverse drug reactions, has proposed the herein-reported guidelines for performing skin testing in CADR in order to standardize these procedures. In each reported case, the imputability of each drug taken at the onset of the CADR and a highly detailed description and characterization of the dermatitis need to be given. Drug skin tests are performed 6 weeks to 6 months after complete healing of the CADR. Drug patch tests are performed according to the methods used in patch testing in studying contact dermatitis. The commercialized form of the drug used by the patient is tested diluted at 30% pet. (pet.) and/or water (aq.). The pure drug is tested diluted at 10% in pet. or aq. In severe CADR, drug patch tests are performed at lower concentrations. It is also of value to test on the most affected site of the initial CADR. Drug prick tests are performed on the volar forearm skin with the commercialized form of the drug, but with sequential dilutions in cases of urticaria. Intradermal tests (IDT) are performed with sterile sequential dilutions (10-4, 10-3, 10-2, 10-1) of a pure sterile or an injectable form of the suspected drug with a small volume of 0.04 ml. Drug skin tests need to be read at 20 min and also later at D2 and D4 for patch tests, at D1 for prick tests and IDT. All these tests also need to be read at 1 week. The success of skin tests varies with the drug tested, with a high % of positive results, for example, with betalactam antibiotics, pristinamycin, carbamazepine and tetrazepam on patch testing, or with betalactam antibiotics and heparins on delayed readings of IDT. The results of drug skin tests also depend on the clinical features of the CADR. The use of appropriate control patients is necessary to avoid false-positive results.

Skin tests with drugs can be of value in investigating patients who have developed cutaneous adverse drug reactions (CADR), but their specificity and relevance remain to be determined. A false-positive result on skin testing can happen if it is not compared to results in control subjects. When performing intradermal tests (IDT), we have determined the lowest concentrations that induce false-positive results for many drugs, including betalactam antibiotics, cephalosporins, other antibiotics or non-steroidal anti-inflammatory drugs. Some drugs in their commercialized form contain sodium lauryl sulfate and can induce irritation when patch tested as such. When patch tested with colchicine at 10% in pet. or with a Cytotec pill (containing misoprostol) at 30% in pet., respectively, 80% of the 29 and 9 of the 10 negative controls developed false-positive results. Lastly, positive results of patch tests with drugs can be related to contact allergy to one of the components of the commercialized form of the drug, without any relevance to the investigation of a CADR, as observed in 2 cases with iodine or avocado oil.

We report a 10-year-old girl in whom Stevens-Johnson syndrome (SJS) (with acute gingivostomatitis and conjunctivitis) was associated with a pustular eruption clinically and histologically similar to Sneddon-Wilkinson subcorneal pustulosis. This is a very rare form of SJS, the true incidence of which is probably underestimated.

In order to confirm the mechanism of skin sensitization to propacetamol, a pro-drug of acetaminophen, 3 patients with allergic contact dermatitis from propacetamol were patch tested with N,N-diethylglycine phenyl ester, an activated form of N,N-diethylglycine. Positive patch tests were observed in all the patients at 10% in pet., while 20 control patients remained negative. This strongly suggests that propacetamol is acting as an activated form of N,N-diethylglycine, transferring this part of the molecule to nucleophilic residues of proteins. This also explains why reactions to acetaminophen have never been observed in patients sensitized to propacetamol.