A multicenter study by the Brazilian Society of Dermatology on a new standard patch test series؆

BACKGROUND AND OBJECTIVESContact allergy is associated with a significant morbidity all over the world. This study was performed to investigate the pattern of sensitization by contact allergens in the local population.DESIGN AND SETTINGRetrospective study to investigate patch test reactivity among patients with clinical diagnosis of contact dermatitis who were referred to the allergy clinic at the King Khalid University Hospital, Riyadh, between April 2008 and March 2010.PATIENTS AND METHODSOf the 196 patients referred to the allergy clinic over the 2-year period, 91 (46.4%) patients reacted to one or more patch test allergens, and these patients were included in this study. The study group included 82 (91.1%) of Saudi nationality and 9 (8.9%) patients of other nationalities. The patch test was performed using the T.R.U.E TEST, containing 24 allergens/allergen mixes.RESULTSOf the 91 cases who reacted positively to one or more allergens, 67 (73.6%) were females with a mean age of 37 (8.3 years) and 24 (26.4%) were males with a mean age of 34 (11.6 years). Thirty-three (36.2%) patients reacted to nickel sulfate, 14 (15.3%) to p-phenylenediamine, 13 (14.2%) to p-tert-butylphenol-formaldehyde resin, 13 (14.2%) to thimerosal, and 9 (9.8%) to colophony. Reactivity against the rest of the allergens was not remarkable. A significantly higher percentage of females reacted to nickel sulfate (84.8% vs 15.2% in males; P=.0001), p-tert-butylphenol-formaldehyde resin (92.3% vs 7.7%; P=.0001), and thimerosal (76.9% vs 23.1%; P=.03).CONCLUSIONSPatch test reactivity to nickel sulfate was high. The pattern of contact allergy observed in this study indicates the need for large-scale investigations to identify local allergens responsible for contact allergy and for formulation of policies directed towards avoidance of exposure.

Contact Sensitization to Allergens in the Spanish Standard Series at Hospital Costa del Sol in Marbella, Spain: A Retrospective Study (2005–2010)

Allergic contact dermatitis (ACD) in children was previously considered to be a rare occurrence. However, the growing number of case reports and cross-sectional studies through the past three decades indicate that ACD is, in fact, a highly relevant diagnosis in children. Furthermore, the frequency of ACD in children seems to be increasing. In 1999, a review of the literature reported prevalence rates of 14.5-70% in selected paediatric populations. The current paper reviews the studies on the prevalence of positive patch test reactions and ACD in the paediatric population during the past decade, and provides an overview of the main findings. We found reported sensitization rates of 26.6-95.6% in selected groups of children. The associated relevance was 51.7-100%. The most common allergens were nickel, cobalt, thimerosal, and fragrance. Tailored patch testing increases the rate of relevant patch test reactions. Children with atopic dermatitis are as frequently sensitized as children with no history of atopic dermatitis, and there are no differences associated with sex. Children and adults can be tested with equal concentrations of patch test allergens. Our findings may support the notion that the prevalence of ACD in children is increasing over time or indicate an increased awareness.

Introdução: A dermatite de contacto alérgica em idade pediátrica, habitualmente considerada pouco frequente, tem sido recentemente objecto de numerosas publicações associadas a um aparente aumento da sua prevalência. Tal pode ser devido a exposição e sensibilização mais precoce a alergénios de contacto ou à mais ampla utilização de testes epicutâneos, cruciais ao diagnóstico desta patologia.Métodos: Com o objectivo de avaliar as características e causas da dermatite de contacto alérgica em idade pediátrica, foram analisados os processos clínicos dos doentes com < 18 anos que efetuaram testes epicutâneos entre Janeiro de 2005 e Dezembro de 2014 na Unidade de Alergologia de Contacto do Serviço de Dermatologia dos HUC. Avaliaram- -se os seguintes parâmetros: sexo, idade, história pessoal e familiar de atopia, localização principal da dermatose, testes positivos a alergénios da série básica ou outros e respectiva relevância, hipótese de diagnóstico e diagnóstico final.Resultados: Foram estudados 106 doentes em idade pediátrica (3,6% do total), 68 do sexo feminino (64,2%) e 38 do sexo masculino (35,8%), quatro com idades compreendidas entre os 3 e 5 anos (3,8%), 28 entre os 6 e 11 anos (26,4%) e 74 entre os 12 e 17 anos (69,8%), 52,8% com antecedentes de atopia e 36,8% com lesões localizadas na face e/ou pescoço. Dos 106 doentes, 51 tiveram pelo menos um teste positivo (48,1%), mais frequentemente no sexo feminino por alergia ao níquel (18,9%). Seguiram-se o cobalto, a p-fenilenodiamina e a mistura de caínas (4,7%) entre os alergénios de série básica e, fora dela, o paládio positivo em cinco crianças. De notar que não observámos testes positivos ao níquel nos últimos dois anos. Doze doentes reagiram apenas a alergénios não incluídos na série básica, sobretudo medicamentos.Discussão: A alergia de contacto e dermatite de contacto alérgica antes dos 18 anos revelaram-se relativamente comuns. O diagnóstico etiológico precoce é importante para evitar a cronicidade das lesões e prevenir possíveis repercussões futuras a nível pessoal e profissional. O conhecimento dos principais alergénios nesta faixa etária poderá orientar medidas preventivas de futuras sensibilizações.

Patch testing is performed to evaluate suspected allergic contact dermatitis. Common wisdom suggests that various allergens cross-react but only a few larger studies have published confirmations of this. The purpose of our study was to identify significant correlations between positive test reactions in a screening series. A total of 1235 patients undergoing patch testing to the Hermal standard series at the Massachusetts General Hospital, Contact Dermatitis Clinic between 1990 and 2006 were investigated. Two or more positive reactions were seen in 411 patients (33.3%). Sensitizations to eight pairs of allergens were found to have significant correlation (P <or= 0.0001). A strong association was observed for cross reactions between formaldehyde and its releasers quaternium 15 and imidazolidinyl urea and between balsam of Peru and fragrance mix. Moreover, significant co-sensitization was identified for potassium dichromate and colophony. Three significant pairings in our study were associations between fragrances and metals. Our data confirm the previously published cross-reactions in the literature between fragrance components, and formaldehyde and formaldehyde-releasing preservatives. The increased numbers of patients with metal and fragrance sensitization can be considered as a random finding due to independent sensitization. Being aware of cross-reacting allergens is essential to success in resolving allergic dermatitis when counseling patients.

Patch testing: Facts and controversies

The true prevalence of allergic contact dermatitis (ACD) in children remains unknown. Our aim was to compare the results of patch tests in children with suspected ACD between two different periods of time and identify possible changes in emerging allergens. We compared contact allergens, gender, age distribution, and personal history of atopic dermatitis (AD), in correlation with the positivity of patch tests, between two equal periods of time (232 children tested during 1980-1993, period A, and 255 children during 1994-2007, period B) in the same region and in the same institution. Patch test positivity was 47.8% in period A, and 60% in period B (p = 0.083). The most common allergens in period A were: nickel sulfate (16.3%), cobalt chloride (8.6%), fragrance mix (7.3%), potassium dichromate (4.3%), and thimerosal only (1.7%). In period B, the allergen distribution was as follows: nickel sulfate (21.56%), thimerosal (18.03%), cobalt chloride (12.9%), potassium dichromate (9.4%), and fragrance mix (4.7%). Girls were more likely to have a positive patch test compared with boys, with reactions in 53% of girls and 39% of boys in period A (p = 0.003), and 61% of girls and 58% of boys in period B (p = 0.691). Twenty-nine per cent of patients with positive results had a personal history of AD in period A and 44% in period B (p = 0.015). Differences in the positivity of allergens between different time periods reflect changes in habits, of allergens exposure or preventive measures.

The patch test results of 61 patients allergic to at least 1 corticosteroid molecule are presented. These contact allergies were detected by testing with several corticosteroids 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 found 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.

To test the screening value of the sesquiterpene lactone (SL) mix in Europe today and describe epidemiological and clinical features of Compositae-sensitive patients, the SL mix 0.1% pet. was included in the standard patch test series in 11 European clinics. 10,695 patients were tested, and 106 (1%) had positive reactions, 74% of which were of current or old relevance. The prevalence of positive reactions varied between 0.1 and 2.7% in different centres. The median age of the 66 females was 51.5 years, and 55.2 in the 40 males. The 20 occupationally sensitized had a higher % of males and a median age of 43 years, whereas 7 UV-sensitive patients had a median age of 72 years. Garden plants were the major suspected sensitizers and the clinical patterns were partly, in accordance with plant dermatoses in general, involving hands, forearms and face, and partly widespread eczema in a large proportion of the patients. More than 1/3 were positive to perfume and/or colophony, possibly reflecting cross-reactivity. With only 1 case of active sensitization and no irritant reactions, the SL mix is a safe allergen and the overall prevalence of positive reactions supports its continued use in the standard patch test series.

Allergic Contact Dermatitis in the Older Adults: A Comparative Cross-Sectional Study.

Diagnosis of allergic contact dermatitis to epoxy can be challenging especially in the occupational context. We present a second case of allergic contact dermatitis (ACD) to benzyl alcohol in an epoxy floor paint.1 A 45-year-old Caucasian male with a past history of psoriasis was referred for hand and wrist eczema. (Figure 1). He had been working in industrial paving for 20 years. In his work he used several products such as cement, sealants and epoxy floor paints. His eczema was considerably worsened at work and improved on holidays. Patch tests were performed with the European Baseline Series and cosmetic, rubber, plastic/glue, epoxy and acrylates series using test preparations from SmartPractice Europe, (Greven, Germany), using IQ ultra chambers® from Chemotechnique MB Diagnostics AB (Vellinge, Sweden) according to ESCD guidelines with an occlusion time of 48 h. We routinely patch test benzyl alcohol along with baseline series as additional GERDA series (french group of dermato-allergology study and research). Positive results were found for benzyl alcohol 10% in softisan 649 (++), diglycidyl ether of bisphenol A (DGEBA) 1% pet (++), 1,6 hexanediol diglycidyl ether 0.25% pet (++), 1,4 butanediol diglycidyl ether 0.25% pet (++), diaminodiphenylméthane 0.5% pet (++) at D3 and D10 (Table 1). A second series of patch tests were performed to isocyanate series which remained negative. The safety data sheets of the floor paints used at work, clearly mentioned the presence of benzyl alcohol in various products confirming current definite relevance of this test. (Table 1). He was advised to avoid the exposure to these products at his workplace, and his hand dermatitis considerably improved. Benzyl alcohol (CAS no. 100-51-6) is a well-known allergen in antiseptic products. Multiple cases of sensitizations in antiseptics have been described by the French network REVIDAL-GERDA.2 It can also be used as a fragrance component, preservative, solvent, food additive and excipient in medicinal products.3 Its presence is not so well known in the construction sector, particularly in epoxy systems. It is generally used as a thinner in epoxy resins (an additive to regulate viscosity) and can be found in the epoxy resin part (A) or the hardening part (B). Benzyl alcohol was not present in any of the patient's personal cosmetic products. The patient's work related eczema could be explained by ACD to benzyl alcohol as well as ACD to several other epoxy compounds. Occupational ACD to benzyl alcohol in epoxy systems has recently been reported in another patient working with similar products for the repair and coating of concrete floors.1 Regular occupational exposure to epoxy products with benzyl alcohol, with an altered skin barrier could explain the sensitization to this allergen. Furthermore, a positive patch test reaction to diaminodiphenylmethane (MDA) may indicate ACD to isocyanates. The safety data sheet of one of his products, a polyurethane sealant, mentioned the presence of diisocyanate de 4,4′ methylenediphenyle, but it was not tested and our patient had negative isocyanate series (with toluene 2,4 diisocyanate [TDI] 2%, diphenylmethane 4,4′ diisocyanate [MDI] 0.5%, isophorone diisocyanate [IPDI] 1%, hexamethylene diisocyanate [HDI] 0.1% and polymeric diphenylmethane diisocyanate [PDMI] 2%). A positive reaction to MDA could also indicate ACD to hydrogenated formaldehyde-benzamine polymer (FBAP, CAS no. 135108-88-2) as described by Suomela, due to structural resemblance or a possible cross allergy.4 The safety data sheet of one of our patient's epoxy products mentioned the presence FBAP, as well as BA, but we could not test it separately to confirm this allergy. In conclusion, this is the second case of hand ACD associated with benzyl alcohol in an epoxy system, and can be considered an emerging allergen of relevance in occupational ACD to epoxy system in the construction sector. Marion Menanteau: Investigation; writing – original draft; writing – review and editing. Lynda Bensefa-Colas: Writing – review and editing. Marie-Noëlle Crepy: Writing – review and editing; supervision. We thank Sylvain Caillol PhD Research Director, CNRS (National Centre for Scientific Research) for his contribution to the discussion. The authors declare that they do not have any conflicts of interest regarding this study. The patient in this manuscript has given informed consent to publication of their case details and photographs.

Eczema en los pies en una consulta de alergia cutánea: estudio retrospectivo de 13 años

The increased frequency of case reports of allergic contact dermatitis from non-permanent black henna tattoos in recent years shows the popularity of this form of body painting. Seven patients presented with allergic contact dermatitis after initial hair or eyelash dyeing. They all had a history of a previous reaction from a black henna tattoo. All were patch tested with the European standard patch test series and the standard supplemental series, as well as special series for dyes and hairdressers. All seven patients showed a positive reaction in patch testing with para-phenylenediamine (PPD) (0.3 % and/or 1.0 % in pet.). Five patients also had positive reactions to other dyes such as aminophenol, para-toluene diamine, disperse orange and yellow and four patients reacted to benzocaine. These were interpreted as cross-reactions. The time from sensitization by the black henna tattoo to the onset of allergic contact dermatitis after hair dyeing was an average of 6.2 years. The most common cause of allergic contact dermatitis after black henna tattoos is PPD. Both the long skin contact and the high concentrations of PPD increase the risk of sensitization. Allergic contact dermatitis may be followed by post-inflammatory hyper- or hypopigmentation, scarring and lifelong sensitization, which can have occupational impact, especially for hair dressers and cosmeticians.

Dear Editor, Allergic contact dermatitis (ACD) is a delayed-type hypersensitivity reaction mediated by T cells.[1] Patch testing remains the gold standard for identifying allergens. Given limited literature comparing ACD across age groups, we analysed epidemiological patterns, allergen profiles, and patch test positivity in adults (18–64 years) and geriatric patients (≥65 years). A retrospective analysis was conducted on 464 patients attending the dermatology outpatient department of a Tertiary Care Centre. All had clinically diagnosed ACD. Patch testing was performed using the Indian Standard Series (Contact and Occupational Dermatoses Forum of India-approved), once active lesions resolved. Test chambers (aluminium) containing allergens in petrolatum (0.5%–100%) were applied for 48 hours. Readings were recorded at 48 hours, 96 hours, and Day 7. Patients discontinued systemic corticosteroids and antihistamines prior to testing. Data were analysed using SPSS Version 18.0. Of the 464 patients, 342 (74%) showed positive patch test reactions—304 adults (89%) and 38 geriatric patients (11%). Male preponderance was noted: 53.9% in adults and 76.3% in the elderly. Hand-foot eczema predominated in adults, whereas localized eczema, especially scalp involvement due to the hair dye, was more common in geriatrics. The most frequent adult allergens were potassium dichromate, nickel sulphate, and para-phenylenediamine (PPD). In the geriatric group, PPD, potassium dichromate, and neomycin sulphate were most common. Polysensitization was more prevalent in adults, involving combinations like potassium dichromate + nickel sulphate and mercaptomix + Mercaptobenzothiazole. Geriatrics showed fewer polysensitivities, often involving medicament-related allergens [Table 1].Table 1: Distribution and allergen pattern of allergic contact dermatitis among adults and geriatricsThis study reveals a distinct age-related variance in allergen sensitivity and patch test positivity, with geriatric patients exhibiting a lower reactivity rate. Immunosenescence—marked by reduced T-cell responsiveness, diminished Langerhans cell density, impaired cytokine production, and decreased antigen presentation—may explain attenuated responses in older individuals.[2,3] Chronic illnesses and polypharmacy further contribute to the immune suppression.[2,3] Our overall positivity rate of 74% exceeds those reported in Sri Lanka (55%)[4] and by Kasumagic-Halilovic and Ovcina-Kurtovic (62%).[5] However, low positivity found may be due to latent sensitization in asymptomatic elderly patients, highlighting the complexity of geriatric immune responses. Scalp involvement was frequently observed in older adults, likely linked to increased PPD exposure from hair dyes. These findings parallel those of Lee et al.,[6] who noted PPD, nickel, and cobalt as major allergens in adult Korean populations. Occupational factors likely influenced adult sensitization—especially among those in construction, leather, and automotive sectors where chromium and nickel exposure are high.[2] In contrast, geriatric sensitization skewed toward medicament-related allergens (e.g., neomycin, lanolin), reflecting chronic disease management and reduced exposure to industrial or cosmetic agents. This is consistent with observations by Tosti et al. and Lee et al., who reported lower sensitivity to metal allergens and heightened sensitivity to therapeutic agents in older adults.[2,6] Extended patch test reading—particularly Day 7—is crucial in elderly patients due to delayed hypersensitivity responses.[7] Piaserico et al.[7] emphasized that late-phase responses may otherwise be missed. Customizing patch series to include medicament and age-relevant allergens like lanolin and neomycin enhances detection in geriatrics.[2,3] Comprehensive drug histories are equally vital to avoid false negatives. International studies reflect regional differences. Németh et al.[8] noted benzoic acid, methylisothiazolinone, wood tar, and balsam of Peru among top allergens in older Hungarian patients, underscoring the role of geographic and demographic variables. The high rate of PPD sensitization in our elderly group likely reflects evolving cosmetic practices, increased life expectancy, and sustained use of hair dyes. Despite lower ACD prevalence in geriatrics, the morbidity impact remains significant due to diagnostic challenges, chronicity, and co-morbidities. Diagnostic accuracy can be enhanced by tailored allergen panels, longer patch test reading intervals, and consideration of age-related immunological changes. Patch test positivity is significantly lower in the elderly due to age-related immune changes and reduced allergen exposure. However, sensitization to therapeutic agents is comparatively higher, emphasizing the need for customized testing strategies in this population. Understanding these differences is the critical for accurate diagnosis, targeted treatment, and effective prevention strategies across age groups. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

Epidemiological survey of contact dermatitis in Italy (1984–1993) by GIRDCA (Gruppo Italiano Ricerca Dermatiti da Contatto e Ambientali)