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Results of patch tests in 337 children aged 1 to 15 performed in our paediatric unit during the past 3 years have been analysed retrospectively in order to optimize the patch test series and to assess their relevance. This study represents the most important single-centre study reported so far over a short period. We found a positive patch test rate of 66%, with a peak incidence among children less than 3 years of age (88% versus 58.9%). The most common allergens were metals, especially nickel, fragrances and, less frequently, rubber chemicals. Concerning nickel, positive reactions rarely correlated with a relevant exposure and were difficult to interpret, especially in patients with atopic dermatitis, who are probably more likely to have irritant or false-positive reactions to metals. Based on the results and their relevance, we propose a shortened standard series of patch tests for paediatric patients.

118 patients with oral lichenoid lesions (OLL) topographically related to dental fillings were patch tested (PT) to reveal contact allergy to restorative materials. 80 (67.8%) patients displayed positive PT reactions to metals of dental filling materials: 76 reactions were found to various mercury compounds, 4 to sodium aurothiosulphate, 3 to stannic chloride and 2 to silver nitrate. The positive patch test reactions appeared more commonly in patients with restricted contact lesions (85.1%, type-1 lesions) as compared to patients with lesions exceeding to the adjacent areas (38.6%, type-2 lesions). The replacement of dental fillings was carried out in 62/80 PT-positive and 15/38 PT-negative patients. 28 out of 62 (45.2%) PT-positive and 3/15 (20%) PT-negative patients showed complete healing of OLL after a mean follow-up time of 16 months. Complete healing occurred in 29/54 (54.0%) type-1 and 2/23 (8.7%) type-2 lesions. Topographical relation between the lesion and the filling material (restricted versus exceeding the contact area) indicated association of OLL lesion and the filling material, which could be further confirmed by patch testing in the majority of patients. The patch test series should include mercuric chloride (0.1%), mercury (0.5%) and mercury ammonium chloride (1.0%), each in pet.

Loss-of-function mutations in the filaggrin gene (FLG) have been associated with reduced skin barrier function, possibly allowing increased penetration of irritants and allergens.To study whether FLG loss-of-function mutation carriers show different rates of sensitization to common type I and IV allergens among patients referred for occupational contact dermatitis of the hands.Four hundred and ninety-six Caucasian patients were genotyped for four FLG null mutations and patch tested with the European baseline series. In addition, 431 patients underwent prick testing with common type I allergens.Overall, 67 patients showed a heterozygous mutation in the FLG alleles R501X, R2447X, S3247X, and/or 2282del4. Sensitization rates for type I allergens from a European prick test series did not show significant differences between FLG loss-of-function mutation carriers and wild-type subjects. For type IV allergens, significantly more FLG loss-of-function carriers were found to be sensitized to lanolin and p-tert-butylphenol-formaldehyde resin.Probably a variety of immunological mechanisms other than that resulting from the filaggrin system have an impact on allergic sensitization to a greater degree. Larger cohorts may be necessary to increase the statistical power of the findings presented regarding type I and IV sensitization.

Reactive dyes are used especially for colouring natural fibres (cotton, silk and wool) that are widely used in Western countries, particularly Italy, in the production of clothes. The aim of our study was to investigate sensitization to the most commonly used reactive textile dyes in patients undergoing patch tests, and to assess the clinical relevance of contact sensitization to these dyes. 1813 consecutive patients underwent patch tests with the GIRDCA standard series and an additional textile series of 12 reactive dyes. 18 of these patients were sensitized to reactive dyes (0.99%) (4 only to reactive dyes). The dyes most frequently responsible for positive patch tests were Red Cibacron CR and Violet Remazol 5R (respectively, 8 and 5 positivities). In 5 cases only was a history of intolerance to particular garments given; of 4 patch tests performed with pieces of garment, 2 were positive. In 1 occupationally-exposed patient, airborne contact dermatitis was suspected. Owing to the lack of up-to-date patch test series, some cases of allergic contact dermatitis from textile dyes are probably misdiagnosed: new colouring agents are continuously introduced to the market, so that a close relationship with textile industry is necessary to improve our diagnostic tools.

In an epidemiological study of occupational dermatitis in 5 different shoe factories, 246 workers were interviewed, examined and patch tested using standard and occupational patch test series. The prevalence of occupational contact dermatitis was 14.6% (36/246): 8.1% (20/246) irritant contact dermatitis (OICD) and 6.5% (16/246) allergic contact dermatitis (OACD). Among the latter, the most common occupational allergens were p-tert-butylphenol-formaldehyde resin and mercaptobenzothiazole. 6% (15/246) presented with hyperkeratosis of the fingertips, while 3.2% (8/246) reported pruritus sine materia (PSM) present only during working hours. 2 workers presented with vitiligo-like leukodermic patches on the backs of their hands and on their forearms. Some jobs were more frequently associated with skin complaints. In the assembly department, OACD was most frequent (11.4%), attributed to contact with adhesives and, to a lesser degree, with rubber and leather. OICD caused by contact with the solvents contained in adhesives and varnishes was most frequent in the assembly and trimming departments (17.1% and 15.6%, respectively). PSM, probably caused by the dust present in the working environment was reported by 33.3% of the workers in the sole-cutting and scraping departments. Hyperkeratosis of the fingertips, as a reaction to the continuous trauma of leather on the skin, was observed most frequently (41.6%) in the sole-cutting department.

Polyfunctional aziridine (PFA) is increasingly used as a water-based cross-linker in 2-component paints, paint primers, lacquers, topcoats and other protective coatings. The cross-linker (PFA hardener) is made by reacting multifunctional acrylic monomer with a highly reactive aziridine compound. During 1992-1993, we came across 2 patients with allergic patch test reactions provoked by PFA hardener. One of the patients was a parquet layer, and the other a printer. Allergic contact dermatitis (ACD) was diagnosed by positive allergic patch test reactions to PFA hardener in a dilution series in pet.:0.3%-1% gave ++ to allergic reactions in both patients, whereas 0.1% gave a weak (+) or questionable reaction (?+), respectively. The methacrylate patch test series was negative in both patients, although gas chromatography/mass spectrometry analysis showed that PFA hardener contained 0.3% of trimethylolpropane triacrylate (TMPTA), a multifunctional acrylic monomer. One of the patients also had symptoms of contact urticaria, and a prick test with PFA hardener (1% aq.) induced a histamine-sized prick test reaction. The positive reactions with the PFA hardener and the negative reactions with the starting chemicals and additives in PFA, namely acrylates, propyleneimine and dimethylethanolamine, indicate that PFA caused ACD. This is in accordance with our previous observations, but differs from the reports of others, whose patients had been sensitized to acrylates present as remnants in the PFA hardener. As test substance, 0.5% PFA hardener in pet. is recommended for patch testing. Testing should be performed in patients with contact dermatitis if exposure to PFA has occurred. Skin prick tests may be of help to detect contact urticaria.

Summary Background. Contact allergy to local anaesthetics is relatively common. Patch testing with benzocaine in the European baseline series is recommended for diagnosis, even though a caine mix has been previously suggested to be superior. Objectives. To assess the frequency and patterns of contact allergy to local anaesthetics by using a caine mix (benzocaine, tetracaine, and cinchocaine) in the baseline series, and evaluate its efficiency as compared with benzocaine alone. Methods. We reviewed the results of 2736 patch tests performed between 2000 and 2010, identifying patients with positive reactions to caine mix or to one of seven local anaesthetics. Results. One hundred and twelve patients (4.1%) had at least one allergic reaction to local anaesthetics; 86 were tested with all seven local anaesthetics, resulting in 71 reactions in 53 patients. Cinchocaine gave the most reactions (50.7%); these occurred as a single reaction in 83.3% of patients, mostly with current or past relevance (97%). Benzocaine represented 22.5% of reactions, many of which were non-relevant (44%) or resulting from cross-reactions with para-compounds. Conclusions. Almost 70% of allergic reactions to local anaesthetics would have been missed if benzocaine had been used as a screening allergen. This study supports a recommendation to replace benzocaine with a caine mix containing cinchocaine in the baseline patch test series.

To assess the incidence of latex allergy in construction workers, we studied all the 230 construction workers who attended our clinic between 1996 and 2000. In the 54 (23.5%) patients who reported any kind of intolerance to rubber gloves or boots, we performed both patch testing with the TRUE Test standard series and a rubber series and prick testing for latex. Latex-specific IgE levels were measured when prick testing was positive. 16 patients (7.0%) had a positive prick test to latex, of whom 14 had allergic contact urticaria from latex (ACUL). All of these 14 patients (6.1%) showed 1 or more positive reactions to the True Test series, which included 1 or more rubber chemicals in 9 of them. The level of specific Ig E to latex was greater than 0.35 kU/L in 15 of the 16 patients. In conclusion, our data suggest that the incidence of latex allergic contact urticaria among construction workers may be as high as that among health care workers. Most of these construction workers with Type I latex hypersensitivity had a concurrent Type IV hypersensitivity to chromate or rubber chemicals, presenting as occupational allergic contact dermatitis, which could have facilitated sensitization to latex.

To investigate the frequency of Compositae sensitivity, the recently-developed sesquiterpene lactone mix (SL mix) was included in the standard patch test series. Patients with positive reactions to this or patients suspected of having a Compositae allergy were supplementarily tested with a Compositae mix, consisting of ether extracts of 5 European Compositae plants. In the first year, 686 patients were tested with the SL mix and 79 with the Compositae mix. A total of 31 Compositae-sensitive patients (4.5%) were found. The frequency of positive reactions to either of the mixes was equal, but only 17 of 30 patients tested were positive to both mixes. Testing with the individual ingredients of the Compositae mix showed frequent positive patch test reactions to feverfew, followed in order by chamomile, tansy, yarrow and arnica. The reason for this distribution is discussed and the results of standard, photo- and other plant patch tests are presented. The only partial overlap between positive reactions to the mixes emphasizes the necessity of supplementary testing in patients suspected of Compositae allergy, as well as the lack of a reliable single screening agent. Since no cases of active sensitization or irritant reactions were seen, both the SL mix and the Compositae mix may be considered suitable for routine screening of Compositae allergy.

BACKGROUND: Patch testing detects delayed-type sensitizations and may show changes in prevalence over time. OBJECTIVES: To compare sensitization prevalence to our baseline series allergens during the years 2000-2004 to results from 1990 to 1994. METHODS: We analysed baseline patch test series allergens from 2000 through 2004. RESULTS: 4094 individuals were patch tested to the baseline series (mean age 45.4 years, males 41.7%). The highest sensitization rates were found for nickel sulfate (19.3%), fragrance mix (10.4%) and Myroxylon pereirae (7.8%). Compared to 1990-1994, methylchloroisothiazolinone (and) methylisothiazoline (MCI/MI) and neomycin sulfate sensitization decreased and lanolin alcohol, thiuram mix and ammoniated mercury sensitization increased. CONCLUSIONS: Current sensitization rates are similar to those across Europe. Reduced sensitizations to MCI/MI and neomycin sulfate and increased sensitizations to thiuram mix and ammoniated mercury chloride may well be because of changes in exposure. The current group comprises a higher proportion affected by leg dermatitis and may thus explain the higher sensitization to lanolin alcohol. Comparing patch results over time shows important changes in sensitization prevalence.

Compositae dermatitis in an allergic contact dermatitis, frequently chronic, triggered by plants of the Compositae family. The condition, which is seen, in particular, in middle-aged and elderly persons, typically starts in the summer months with an acute eczema either corresponding to areas exposed to light and air, or corresponding to areas of plant contact; it disappears spontaneously during the fall of the year. Repeated exposure over a number of years may cause severe intractable dermatitis affecting the patient throughout the year. The responsible allergens are sesquiterpene lactones, and investigations to date indicate that the frequency of the allergy is similar to that seen with some of the contact allergens of the standard patch test series. The diagnosis, however, is difficult, partly due to the fact that the clinical picture may be mistaken for a photodermatosis, and partly owing to the difficulty in obtaining commercially available allergens for patch testing. The diagnosis is therefore based on testing with plant extracts, which can cause pronounced local reactions and possibly active sensitization. A survey is given of the possible modes of sensitization, sex and age distribution, the relationship to photosensitivity and atopy, as well as the possible treatment. It is concluded, on the basis of the chronic nature of the disease, and the diagnostic and treatment problems, that continued intensive research into the condition is urgently needed.

Pathophysiological variability affects the results of patch testing. In addition, even a minimal degree of test-imprecision due to this variability has a number of important statistical consequences for the analysis and interpretation of any patch test data set. One such statistical phenomenon that is often overlooked is the dependence of the positive predictive value (i.e., the predictive value of a positive patch test) on sensitivity and specificity, the impact of which is heavily dependent on the proportion of truly allergic subjects that are studied. A 2nd important issue is the fact that patch testing is performed in series, which means multiple tests. If we assume, for example, a patch test series of only 10 allergens, then it can be demonstrated that there is a random probability of over 40%) to find, simply by chance, for at least 1 allergen, a statistically significant difference between 2 groups of patients. Comparison of the results of series between patients calls for statistical adjustments in order to prevent erroneously positive differences and/or associations.

Pathophysiological variability affects the results of patch testing. In addition, even a minimal degree of test-imprecision due to this variability has a number of important statistical consequences for the analysis and interpretation of any patch test data set. One such statistical phenomenon that is often overlooked is the dependance of the positive predictive value (i.e., the predictive value of a positive patch test) on sensitivity and specificity, the impact of which is heavily dependent on the proportion of truly allergic subjects that are studied. A 2nd important issue is the fact that patch testing is performed in series, which means multiple tests. If we assume, for example, a patch test series of only 10 allergens, then it can be demonstrated that there is a random probability of over 40% to find, simply by chance, for at least 1 allergen, a statistically significant difference between 2 groups of patients. Comparison of the results of series between patients calls for statistical adjustments in order to prevent erroneously positive differences and/or associations.

A national database on chemical products (the Danish Product Register (PROBAS] was searched for products containing selected contact allergens. As of June 1990, a total of 47,400 products were registered in PROBAS. About 27,800 of these were fully computerized. A list of 43 allergens was established, based on the European standard patch test series, substances classified "May cause sensitization by skin contact", text books on contact dermatitis, and clinical experience. The number of products in which each of these allergens was registered varied from 30 to more than 1300. Formaldehyde was registered in all product categories included in the study. Benzyl alcohol, stearic acid, epoxy compounds, diethylenetriamine and butylated hydroxytoluene were registered in more than half of the product categories. Paints/lacquers and hardeners for two-component products (paints, glues, fillers, etc.), cleaning agents, binders, adhesives/glues and toiletries made up the most frequently registered product categories for the allergens listed. The possibilities and limitations of database information on chemical products are discussed.

3 corticosteroids have so far been tried as markers for corticosteroid contact sensitivity: hydrocortisone, tixocortol pivalate and hydrocortisone-17-butyrate. The present study compared these steroids for screening in addition to a standard patch test series. Of 727 patients, 28 (3.9%) reacted to tixocortol pivalate and 10 (1.4%) to hydrocortisone-17-butyrate; hydrocortisone gave an allergic reaction in 2 of 521 (0.4%) patients. Serial dilutions suggested that tixocortol pivalate, not marketed in Finland, caused allergic reactions which could possibly be cross-reactions to hydrocortisone. In contrast to previously published data, frequent cross-reactions occurred with hydrocortisone-17-butyrate and tixocortol pivalate. All allergic reactions to other corticosteroids found by testing with tixocortol pivalate concurred with reactions to hydrocortisone-17-butyrate. The study suggests that the most effective choice for routine testing for corticosteroid contact sensitivity would be both tixocortol pivalate and hydrocortisone-17-butyrate.

BACKGROUND: Buprenorphine is a low-molecular-weight, lipophilic, opioid analgesic. The transdermal delivery system (TDS) containing it has skin irritation potential, but at least two cases of contact allergy to the active principal have been described previously. OBJECTIVE: To confirm allergic contact dermatitis from transdermal buprenorphine (TDB) in five older patients suffering from chronic pain and who developed persistent, pruritic erythematous plaques at the contact sites, with two of them also presenting with a generalized skin eruption. METHODS: Besides the baseline patch test series, all five patients were tested with the TDB, four of whom were also tested with the placebo transdermal delivery system as provided by the manufacturer; one patient was also tested with other preparations containing buprenorphine. RESULTS: All reacted to the TDB containing the active principal, the placebo being negative in the four patients tested. The patient tested with the other buprenorphine preparations did react positively to them as well. Tests with TDB in 28 healthy controls were negative. CONCLUSION: We report five cases of delayed hypersensitivity reactions to a TDS containing buprenorphine. Such adverse reactions might be under-reported. A fentanyl-containing TDS is a good alternative in these cases. ispartof: Contact Dermatitis vol:59 issue:6 pages:366-369 ispartof: location:England status: published

Background: Correlation of several patient factors with contact sensitization to nickel, cobalt, chromate, and other metal allergens has not been reviewed in the Taiwanese population. Objectives: A retrospective analysis was performed to define the characteristics of patients with positive patch tests to metals in a tertiary referral medical centre between 1978 and 2003. Patients and Methods: Patch test data of 3559 patients at a medical centre in Taiwan from 1978 to 2003 were retrospectively analysed. Contact sensitization to metals was defined as a positive reaction to at least one of the metal substances in the patch test series. Chi-squared test, Fisher’s exact test, and multivariate logistic regression were used for statistical analysis. Results: Female patients were more likely to have contact sensitization to metal allergens except chromate or mercurochrome. Patients who reacted to chromate were more likely to be male, with an occupational correlation, older age, and a site of predilection towards the extremities. Within the first and sixth decades of age, thimerosal and chromate were the leading causes of metal contact sensitization, respectively. Nickel was the major metal sensitizer among the other age groups. Conclusions: Several patient factors were characterized related to metal sensitization in the Taiwanese population. The sources of exposure were further discussed.

Background: A history of prolonged use of topical antimicrobials is common among patients with positive patch test reactions to gentamicin and to aminoglycosides. Objectives: The aim of this study was to show sources of gentamicin sensitization in patients with positive patch test reactions to gentamicin. Patients and methods: About 7814 patients were patch tested with a baseline patch test series and 620 of them were further tested with gentamicin. The clinical histories, concurrent contact sensitivities, and sources of sensitization are analysed among these patients. Results: Positive patch test reactions to gentamicin were seen in 29/620 patients, most of whom (18/29) also reacted to neomycin and to kanamycin (7/29). Mean age of the gentamicin-positive patients was 62 years, but three young operating room nurses with hand dermatitis had a history of gentamicin exposure from bone cement. Among the 11/29 neomycin-negative patients, a history of exposure to different aminoglycosides was apparent, and one patient had a history of systemic netilmicin-medication-associated exanthema. Conclusions: Positive patch test reactions to gentamicin reflect sensitization to different aminoglycosides for which gentamicin seems to represent a sensitive indicator. Gentamicin sensitization may result from occupational exposure to gentamicin containing bone cements or from systemic medication with aminoglycosides.

506 patients were suspected of being allergic to corticosteroid medicaments in our clinic during the 22 years from 1967 to 1988. Patch tests were performed in these patients. Scratch tests, intradermal tests, and challenge tests were also carried out in some cases. 69 patients showed positive reactions to corticosteroid products (as is). 18 were allergic to the corticosteroid itself and 44 were sensitive to vehicle components or other active ingredients. In 7 cases, the allergen could not be detected. Patients who were allergic to corticosteroids were tested for their cross-sensitivity with our corticosteroid patch test series. Cross-reactions tended to occur between members of the same corticosteroid type, and some of the combinations of different corticosteroid types cross-reacted with each other. Corticosteroid-sensitive cases have increased in number during these 22 years. Corticosteroid sensitivity is not as rare as formerly thought.

This study comprises 40 patients with skin disorders from current or previous occupational exposure to epoxy resin compounds (ERC) during 1984-1988. ERCs were the 3rd most common cause (32 of 264 cases: 12.1%) of currently relevant allergic contact dermatitis: 23 cases from epoxy resins based on the diglycidyl ether of bisphenol A (DGEBA-ERs), 5 from reactive diluents, 1 from amine hardeners (DETA), and 3 from epoxy acrylates. 2 cases (0.8%) of irritant contact dermatitis were due to ERCs. Methyl hexahydrophthalic anhydride (MHHPA, an epoxy hardener) caused 1 case of contact urticaria. Previously relevant occupational allergic contact dermatitis from DGEBA-ERs was detected in 5 cases. On patch testing, ERC allergens gave the following positive reactions: epoxy resin of the standard series in 35 cases (4.0% of 870 tested), epoxy reactive diluents in 10 (7.1% of 140), cycloaliphatic epoxy resins in 4 (11.1% of 36), epoxy acrylates in 4 (4.5% of 88), and amine compounds commonly used as epoxy hardeners in 17. Despite extensive patch test series, testing with patients' own ERCs remains important.

This study attempts to demonstrate the existence of allergic contact dermatitis from grass, and to develop a patch test series to screen patients with grass intolerance. 6 common grass species from lawns and military training areas were collected. Solvent extracts of polar, non-polar and volatile fractions were prepared and used for patch testing in 20 control subjects and 46 patients with a history of grass intolerance. The 20 controls had negative responses to patch testing. 5 out of 46 patients had positive patch tests to Axonopus compressus (carpet grass), Ischaemum muticum (seashore centipede grass), Imperata cylindrica (lalang), Panicum maximum (Guinea grass) and Pennisetum purpureum (elephant grass). Reactions to the non-polar fraction for all 5 species were noted. This study demonstrates the existence of allergic contact dermatitis from various common species of grass. In our series, this is seen in 11% of those with a history of grass intolerance.

Glyoxal is a dialdehyde that is used as a disinfectant in health care and dentistry work. Allergic contact dermatitis from glyoxal has been described in these occupations. We analysed our patient data from 1998 to 2004 for allergic reactions to glyoxal. 20 patients had allergic reactions to glyoxal on patch testing. 5 of these patients worked in dentistry and 4 of them had present exposure to glyoxal. 9 patients were machinists without obvious exposure to glyoxal. A grinder with work-related facial dermatitis is described in detail. The chemical analysis of air samples from his workplace revealed 9.4-21 microg/m3 glyoxal. Glyoxal was also present in the used metal-working fluid, and apparently it had been formed during grinding. The remaining 6 patients worked in miscellaneous occupations and had no present exposure to glyoxal. Glyoxal is irritant on patch testing. Especially, solitary reactions to glyoxal 10% in aq. may be false-positive irritant reactions. 9 (45%) of our patients reacted to formaldehyde or glutaraldehyde. Glyoxal is an important allergen in dentistry and medical care, and we recommend it to be added to the antimicrobial patch test series. It also seems to be a 'hidden' allergen in the metal industry.

High frequencies of contact allergy to fragrance ingredients have been reported in recent years. Only approximately 70-80% are detected by fragrance allergens in the standard patch test series. This investigation compares the patch test reactions to fine fragrances with reactions to fragrance mix (FM), balsam of Peru (BP) (Myroxylon pereirae resin) and a fragrance series. 641 consecutive patients with eczema were patch tested with the European standard series and with selected fine fragrances. Those who were positive to 1 of the fine fragrances or the FM or BP were also tested with the fragrance series. 95 (14.8%) patients were found to have a positive patch test reaction to FM or BP; 41 (6.4%) had positive results to fragrance no. 1 and 29 (4.5%) to no. 2. 9 (9.5% of the 95 positive patients) had a positive reaction to fine fragrances and a negative reaction to all other fragrance allergens in the standard series. These findings indicate that testing with fine fragrances can add to our evaluation of fragrance-sensitive patients.

Udgivelsesdato: 2003-Jun Hydroxyisohexyl 3-cyclohexene carboxaldehyde, also known as Lyral, is a fragrance ingredient identified as the cause of contact allergic reactions in 2-3% of eczema patients undergoing patch testing. Lyral has been included in the standard patch test series in many clinics due to its importance as an allergen. It has been used without restrictions in cosmetic products, until now. In the present study, the dose-response relationship of Lyral contact allergy was studied with doses relevant for normal exposure in cosmetic products. 18 eczema patients, who previously had given a positive patch test to Lyral 5% petrolatum, were included along with 7 control subjects. All cases were tested with a serial dilution of Lyral in ethanol 6% to 6 p.p.m and subjected to a 2-week, repeated open application test with a low dose of Lyral in ethanol. In the case of no reaction, this was followed by another 2 weeks of testing with a higher dose. The test was performed at the volar aspect of the forearm. In 16 of 18 cases (89%), a positive use test developed, 11 reacting to the low and 5 to the high concentration. None reacted to the vehicle control of ethanol applied to the contralateral arm. All controls were negative to both the test solutions of Lyral and the ethanol control. The difference between the test and the control group was statistically significant (Fisher's test, P < 0.001). It is concluded that Lyral at the current usage levels is inducing sensitization in the community. The same levels were shown to elicit allergic contact dermatitis in almost all sensitized individuals. A significant reduction in usage concentrations is recommended to prevent contact allergic reactions.

To assess the incidence of latex allergy in construction workers, we studied all the 230 construction workers who attended our clinic between 1996 and 2000. In the 54 (23.5%) patients who reported any kind of intolerance to rubber gloves or boots, we performed both patch testing with the TRUE Test standard series and a rubber series and prick testing for latex. Latex-specific IgE levels were measured when prick testing was positive. 16 patients (7.0%) had a positive prick test to latex, of whom 14 had allergic contact urticaria from latex (ACUL). All of these 14 patients (6.1%) showed 1 or more positive reactions to the True Test series, which included 1 or more rubber chemicals in 9 of them. The level of specific Ig E to latex was greater than 0.35 kU/L in 15 of the 16 patients. In conclusion, our data suggest that the incidence of latex allergic contact urticaria among construction workers may be as high as that among health care workers. Most of these construction workers with Type I latex hypersensitivity had a concurrent Type IV hypersensitivity to chromate or rubber chemicals, presenting as occupational allergic contact dermatitis, which could have facilitated sensitization to latex.

In 1990, a random sample of 567 persons of the 15-69-year-old population living in the Western part of Copenhagen County, Denmark, was patch tested in a cross-sectional study. In 1998, a follow-up study was performed. Out of 540 invited, 365 (68%) were re-patch tested. In the follow-up study, the persistence of allergic contact sensitivity, defined as 1 or more positive patch tests in both surveys, was 71% (37 out of 52 subjects). Nickel allergy persisted in 79% (19 out of 24 subjects), while 60% (21 out of 35 subjects) had a positive patch test reaction to 1 or more allergens, other than nickel, in both surveys. The lowest persistence was 50% (5 out of 10 subjects) and this was found for patch test reactivity to 1 or more of the cosmetic ingredients included in the patch test series. 8 years after the baseline study had demonstrated allergic contact sensitivity, 71% of the subjects still had at least 1 positive patch test. Nickel allergy persisted in 79%. Allergen avoidance should probably be lifelong to prevent elicitation of contact dermatitis.

Pathophysiological variability affects the results of patch testing. In addition, even a minimal degree of test-imprecision due to this variability has a number of important statistical consequences for the analysis and interpretation of any patch test data set. One such statistical phenomenon that is often overlooked is the dependence of the positive predictive value (i.e., the predictive value of a positive patch test) on sensitivity and specificity, the impact of which is heavily dependent on the proportion of truly allergic subjects that are studied. A 2nd important issue is the fact that patch testing is performed in series, which means multiple tests. If we assume, for example, a patch test series of only 10 allergens, then it can be demonstrated that there is a random probability of over 40%) to find, simply by chance, for at least 1 allergen, a statistically significant difference between 2 groups of patients. Comparison of the results of series between patients calls for statistical adjustments in order to prevent erroneously positive differences and/or associations.

A survey of occupational dermatoses, based on a questionnaire, clinical examination and patch testing, was carried out among present and former employees in a plant producing binders for glues and paints. The binders are chemically based on vinyl acetate and/or acrylates. Preservatives are needed and those based on methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) are the most commonly used. The questionnaire was answered by 83 out of 85 present employees (97.6%) and 12 out of 15 former employees (80.0%). 76 of the present (89.4%) and 11 of the former employees (73.3%), respectively, participated in the clinical examination and patch testing, which was conducted with a standard test series and chemicals from the work environment. Occupational dermatosis was diagnosed in 22 present workers (28.9%). Irritant and allergic contact dermatitis was demonstrated in 9 (11.8%) and 13 (17.1%) employees, respectively. Occupational contact allergy to acrylates and formaldehyde was detected in 3 workers and 1 worker, respectively. 12 individuals (9 present and 3 former production workers) had an occupational contact allergy to MCI/MI. 4 of the present workers had spilled Kathon LX on their skin resulting in chemical burns and allergic contact dermatitis. In total, the figure for occupational skin diseases among all present production workers was 40.4%.

Bioban P 1487, consisting of the 2 active ingredients 4-(2-nitrobutyl)-morpholine (M) and 4,4'-(2-ethyl-2-nitro-1,3-propanediyl)-bis morpholine (DM), is a preservative recommended for mental working fluids. The aims of this study were to assess the frequency of contact allergy to Bioban P 1487, when added to a standard patch test series, as well as to test the individual active ingredients in patients sensitized to Bioban P 1487. Of the patients consecutively tested, 1.5% reacted positively to Bioban P 1487. Positive test reactions were noted in only 4 of 12 Bioban P 1487-sensitized patients tested with the individual active ingredients. Both active ingredients are contact sensitizers, but in most patients with this contact allergy it remains difficult to identify the sensitizing hapten.

5 non-disperse azo dyes, used for colouring natural fibers, were added to the standard patch test series, as 5% pet. Preparations, 1814 consecutive patients attending the patch test clinic were patch tested, of whom 16 (0.88%) reacted to the newly added dyes: 8 to Direct Orange 34. 5 to Acid Yellow 61. 2 to Acid Red 359 and 1 to Acid Red 118. On the basis of clinical history and results of patch tests with pieces of rubrics, contact sensitization to non-disperse azo dyes seemed to be related to the appearance of skin lesions at least in 8 subjects. We conclude that systematic exploration of the sensitizing potential of textile dyes, selected after careful investigation, can provide additional information on the frequency of occurrence of textile dye dermatitis, supporting individual investigation in sensitized subjects.

By and large, positive patch tests with thimerosal lack clinical relevance and should cause concern neither to the dermatologist nor to the patient. The substance should be retained in standard test series for scientific purposes, but on clinical grounds its inclusion does not seem to be indicated. Nevertheless, the phenomenon is intriguing in its own right.

The patch test results of hi patients allergic lo at least 1 corticosteroid molecule are presented. These contact allergies were detected by testing with several corticosteroid s included in our standard patch test series between February 1988 and December 1990. Whenever possible, further investigations were conducted by means of a more complete corticosteroid series. We (mind corticosteroids to be the 7th most frequent allergen, positive results being obtained in 2.9% of all patients referred to our contact dermatitis unit. In this series, budesonide was the most common allergen and often gave simultaneous reactions with other corticosteroids.

The Allergen Bank supplies dermatologists on request with special contact allergens for aimed patch testing of suspected contact dermatitis patients. Easy access to patch test materials beyond the standard patch test series makes it possible for the dermatologists to make an early diagnosis of special cases of allergic contact dermatitis. The Allergen Bank was established in 1992, and the concept described in Acta Derm Venereol 1996; 76: 136–140. The Allergen Bank service is financed through an annual subscription fee, and about 60 Danish dermatologists are currently subscribers.The use of the service has increased steadily over the years. In average, the dermatologists order 6–7 allergens for each patient. The dermatologists use pattern of the bank service varies considerably, probably reflecting what they have available in their clinic of extra allergens beyond the standard series, as well as their patient selection and interest in contact dermatitis. Based on the test results reported back from the dermatologists to the Allergen Bank a total of 197 positive reactions from 107 different contact allergens were found in 2002. This is a yield of approximately 7% positive patch tests related to the number of allergens ordered. The pro's and con's of the Allergen Bank function will be reviewed.

Objectives: To identify substances and tonnage data for use for hair dyes registered in Europe. To predict the sensitization potential of each substance and to rank the substances due to their sensitization potential. Further to group the substances in clusters based on their physical chemical properties with a cluster analysis. Methods: The Inventory list of Cosmetics Ingredients (INCI), new regulation on cosmetics, tonnage data for use and Toxnet were used to identify and quantify the hair dyes. Salts were disregarded. A QSAR (Qualitative structure-activity relationship) model called TOPS-MODE, based on local lymph node assay (LLNA) data and physical chemical properties were used to predict the sensitization potential and make a cluster analysis. Results: Out of 315 hair dye substances 229 meet the inclusion criteria. Most of the hair dye substances 75% were predicted to be strong to moderate sensitizers. Less were predicted to be weak 22% and only a small part 3% were predicted to be extremely weak or non sensitizing. The 8 most used hair dye substances were predicted to be strong to moderate sensitizers. Ppd is the most used hair dye allergy marker but some azodyes were predicted to be more potent than para-phenylenediamine (ppd). Conclusions: Most hair dye substances are predicted to be strong to moderate sensitizers, which explain why some people gets hair dye dermatitis. A patch test series with potent, much used azodyes, might prove useful in diagnosing ppd-negative patients, with hair dye allergy. The cluster analysis grouped the substances which can be helpful choosing substances for clinical patch test.

Objective and methods: We review patch test results from two special patch test series for plant allergens, ‘plant extracts’ and ‘allergenic plant chemicals’, provided by Prof. Hausen (Germany) and tested in 1992–2003. The standard series contained Sesquiterpene-lactone mix (SL mix) since 1993 (3/1998–10/1999 excluded) and Compositae mix since 3/1998. We present the cases where either SL mix or Compositae mix gave an allergic reaction and where, in addition, the series of plant extracts was tested. Results: SL mix and Compositae mix were tested to 900 patients. Among them, plant extracts were tested in 122 and plant chemicals in 104 cases. 30 patients had an allergic reaction to Compositae mix and 17 to SL mix as well. In the plant extract series, there were more than 5 allergic reactions to feverfew(21), true chamomile(21), arnica(18), chrysanthemum(18), laurel bay leaf(13), tansy(12), gaillardia(9), yarrow(8) and pot marigold(7). In the plant chemical series, there were 9 allergic reactions to parthenolide and single reactions to primin, chlorophorin and Mansonone A. Conclusions: Compositae mix gave a positive test reaction always together with SL mix, which gave a positive reaction in only part of these cases. The concentration of Compositae mix was lowered from 6% to 3% in 1/1999 because of cases of active sensitisation. The lower concentration seems to be reliable for detecting allergy, although it still causes active sensitisation.

139 workers from 3 ceramics factories underwent dermatological and allergological examination, using standard and occupational patch test series, in order to evaluate the prevalence of dermatitis and contact sensitization, to identify the most important sensitizing substances in the ceramics industry, and to correlate the results with possible risk factors such as atopy. Hand dermatitis had affected 37% of the subjects examined. 27% of the workers were sensitized to 1 or more allergens. Of 52 subjects with dermatitis, 37% had allergic contact dermatitis and 63% irritant contact dermatitis. 18 subjects were found to be sensitized without showing any previous or present clinical symptoms. Atopy tended towards correlation with the overall incidence of dermatitis, though not with the prevalence of sensitization.

UV filters are currently the most common photoallergens (1, 2), particularly the benzophenones (2–7). Recently, the concentration of UV filters in the GIRDCA photopatch test series has been increased from 2% to 10% pet.

A standard patch test series was tested for 7 years (1977–1983) in a total of 11,962 patients. The annual frequency of positive reactions to the compounds tested was assessed for the total and for males and females separately. During the observation period, there were significant increases in positive reactions in the total group from 6.2% to 12.7% for nickel sulphate. from 5,3% lo 7.0% fur balsam of Peru and from 3.8% to 6.5% for potassium dichromate, reflecting significant changes in both sexes. The frequency of positive reactions to wool alcohols, formaldehyde, neomycin sulphate, paraben mix and gentamycin sulphate significantly increased, while that of positive reactions to clioquinol, mercuric chloride arid turpentine peroxide significantly decreased in cither males or females, sometimes leading to significantly changes in the total group.

To determine the incidence of patch test reactions to copper, 2% copper sulphate was included in our routine patch test series. The allergic potential of copper sulphate was evaluated by the guinea pig maximization test method (GPMT). 13 of the 1190 eczema patients showed reactions (1.1%), but they were considered non-relevant. 3 series of GPMT demonstrated that copper sulphate was a grade I allergen. A critical review of the literature disclosed that several reports on cases of allergic contact dermatitis to copper must be regarded as uncertain or non-relevant. 4 cases were considered relevant and another 20 cases probably relevant. It is suggested that a test reaction to copper sulphate should be verified by a serial dilution test (SDT). Furthermore, the sensitivity of patients to other metals should be stated, so that one can be aware that false positive reactions from metal impurities, especially nickel, in the copper salt used for testing may occur.

During a 22-month period, 2.0% cadmium chloride in distilled water was included in our routine patch test series. Twenty-five of 1502 eczema patients showed reactions (1.7%), but none had any relevant history. At serial dilution test only one patient reacted to 1.0% cadmium; all the other dilutions applied gave negative reactions. Analysis by atomic absorption spectrophotometry of the cadmium chloride used for patch testing showed that it contained less than 1 microgram/g of chromium, copper, cobalt and nickel. The conclusion is that no certain case of contact allergy to cadmium chloride has been revealed. An experimental study using the guinea pig maximization test is in progress.

We showed earlier that most patients with contact dermatitis due to corticosteroids show cross-reactions when patch tested with hydrocortisone-17-butyrate (H-17-B). To test whether H-17-B could be used for detecting topical corticosteroid allergy, we screened patients undergoing routine patch testing with H-17-B. Patients with clearly allergic or doubtful/mildly irritant patch test reactions to H-17-B, and with a history suggesting topical corticosteroid allergy, were further tested with a large panel of steroid preparations. 20 out of 4039 patients (0.5%) showed definite allergic test reactions to corticosteroids. A further 165 patients with clinically suspected corticosteroid allergy were directly tested with a panel of steroid preparations; 14 patients showed positive patch test reactions. Altogether, 33 out of 34 patients with corticosteroid allergy had positive test reactions to H-17-B. Inclusion of 1.0% H-17-B in ethanol in the standard patch test series improves the diagnosis of topical corticosteroid hypersensitivity.

To determine whether the prevalence of allergic reactions to certain preservatives warrants their inclusion in a routine series for patch testing, a tray of 14 preservatives was tested in 501 consecutive suspected contact dermatitis patients. More than 1% positive reactions were found with DMDM hydantoin, Kathon CG, and alkyl trimethyl ammonium chloride only. The concentration of alkyl trimethyl ammonium chloride (0.1% aqua) was considered too high. Of 6 patients reacting to the formaldehyde releaser DMDM hydantoin, 4 were positive to formaldehyde. Kathon CG may be an important allergen in the Netherlands, and it is worthwhile for dermatologists there to add it to the standard test series. The recent inclusion of quaternium-15 in the ICDRG standard series appears to be of little value to them.

The quinoline color D & C Yellow No. 11 was added to a standard test series. Of 88 patients tested with 1 % in PEG. four showed unexplained positive test reactions. One patient had a “flare-up” reaction after 1.4 days. At rechallenge he reacted to a dilution down lo 0.00001%. Simultaneous reaction with the chemically related commonly used food color Quinoline Yellow (E 104) suggests cross-sensitivity.

In a joint study, 2061 patients (1346 women and 715 men) were patch tested with chlorhexidine gluconate 1% in water, included in a standard test series. 48 patients (2.3%) showed a positive reaction. These were relatively more common in men (3.2%) than in women (1.9%). Positive reactions were most common in patients with leg eczema (6.8%) or leg ulcer (10.9%). Of the 48 patients who were patch test positive, 14 (2 with leg ulcer) were retested with chlorhexidine gluconate 0.01 and 1%. Only one with a leg ulcer was positive. These findings indicate that false positive reactions, known as "the excited skin syndrome", may arise from testing eczema patients in a standard series. The sensitizing potential of chlorhexidine may be very low, but the potential in patients with an eczema or ulcer of the leg has to be further evaluated.

605 consecutive patients were patch tested with the standard CDRG test series and with a 10% alcoholic solution of propolis. Positive allergic reactions to propolis were observed in 25 patients (4.2%); thirteen of them exhibited a simultaneous positive patch test to balsam of Peru. In view of the relatively high incidence of allergic reactions and the appearance of pseudo-cross-sensitivity to another common allergen, balsam of Peru, propolis should not be used in topical medicaments or as a component of cosmetic preparations.

The results obtained with a standard patch test series in a group of agricultural workers is compared with a control group. Statistically significant differences in the frequency of several allergens were found. The possible causes of these differences are discussed.

During December 1985 and February 1986, an investigation was carried out into skin diseases among workers in a plant producing decorative equipment built of paper sheets impregnated with resol resins based on phenol and formaldehyde (P.F-R). A questionnaire was sent to all 238 employees and it was answered by 218 (91.6%). Previous and current dermatoses were reported by 98 workers and 89 of these were examined and patch tested. The patch testing was conducted with a standard test series and products from the working environment and revealed contact allergy to P-F-R in 9 persons and to formaldehyde in I. Besides these 10 individuals with occupational allergic contact dermatitis, occupational dermatoses were diagnosed in an additional 20 workers; irritant contact dermatitis in 19 and chemical burn in L. In total, the figure for occupational dermatoses was 30 (12.6%).

3 female workers in a brush factory developed contact allergy from a 2-component epoxy glue containing epoxy resin (37% w/w), reactive diluents: i.e., l,4-butanediol diglycidyl ether (BDDGE) 3%, glycidyl ethers of aliphatic alcohols (Epoxide 8) 0.03% and phenyl glycidyl ether (PGE) 0.01%: and inert fillers. All 3 patients were positive to the resin component of the glue and to BDDGE, indicating that BDDGE was the main allergen. 2 of the patients reacted to PGE, but none to the 3rd reactive diluent (Epoxide 8) in the glue. 2 of the patients did not react to epoxy resin, indicating that BDDGE may be an even stronger sensitizer in humans than epoxy resin, and that it does not cross-react with epoxy resins. Permeation studies revealed that BDDGE penetrates disposable PVC and rubber gloves in less than 30 min; thus, contaminated gloves should be replaced immediately. Reactive diluents should be included in patch test series if contact allergy to epoxy products is suspected.

The masseur of a famous ballet company developed severe contact dermatitis of his hands. Skin testing yielded a surprising result: not one of the suspected 23 different massage creams that the members of the ballet made him use gave a positive reaction. Only colophony, which was included in the standard test series, was positive. Colophony is regularly used on the shoes of dancers on wooden stages to prevent slipping. The masseur had to change his place of employment.

Common emulsifiers were tested in over 1,200 patients with eczema. Triethanolamine stearate tested at 5% in petrolatum caused irritant reactions in 9.5% of the patients. On the other hand, non-ionic emulsifying agents tested at 10-20% produced irritation in only a few cases. Allergic reactions were found in 2.1% of those tested. Lanette, sorbitan sesquioleate, the Spans, polyoxyethylene oxypropylene stearate, polyoxyethylene sorbitol lanolin derivative, and triethanolamine stearate each elicited allergic reactions in 0.3-0.7% of the cases. The Tweens caused an allergy in only two cases, but glycerol monostearate caused no reaction at all. Five out of six patients sensitive to sorbitan sesquioleate reacted positively to the Spans as well. The patients allergic to one or more emulsifiers were also sensitive to several other substances included in our routine test series with the exception of four patients who reacted only to the emulsifying agents.