Prevalence of allergen sensitization detected by patch tests.

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.

Allergic Contact Dermatitis in Children With and Without Atopic Dermatitis

Evaluation of Nickel Allergic Reactions to the Essure Micro Insert: Theoretical Risk or Daily Practice?

Background There is emerging evidence of a relationship between atopic dermatitis (AD) and allergic contact dermatitis (ACD), though the data available are scarce with conflicting viewpoints. We explored the occurrence of contact hypersensitivity among children with atopic dermatitis by patch testing them with the Indian standard series and tried to correlate the presence of contact hypersensitivity with the clinical severity of AD in these children. Methods In this single-centre, cross-sectional study, children between 6 months and 12 years diagnosed with atopic dermatitis were included and patch tested with the Indian standard series. Outcome parameters were the proportion of patients having positive patch-test reactions, the proportion of positive patch-test reactions for each allergen and factors associated with patch test positivity in atopic dermatitis. Results Of the 136 patients, 80 were boys. The mean age of the study population was 5.6 ± 3.2 years. Twenty-eight (20.6%) patients had patch test positivity at 96 h. Fragrance mix was the commonest allergen, followed by potassium dichromate, cobalt chloride hexahydrate and nickel. SCORing atopic dermatitis (SCORAD) was significantly higher in patients with positive patch tests as compared to patients with negative patch tests (P = 0.009). Conclusion Greater disease severity in atopic dermatitis was found to be associated with patch test positivity. Limitations Inability to establish relevance in about 50% of the patients was a limitation of our study. Follow-up data regarding the impact of allergen avoidance is not available.

Facial dermatitis is commonly encountered in dermatologic practice. It is sometimes difficult to manage because its causative factors may be multiple and difficult to diagnose. This study was designed to identify the characteristics, patch test results, and final diagnoses of facial dermatitis patients who were referred to a contact dermatitis clinic and to identify factors associated with facial allergic contact dermatitis (ACD). We retrospectively reviewed case records of facial dermatitis patients who underwent patch testing at the clinic during the period from July 2006 to June 2011. Of the 891 patients patch-tested, 244 (27.4%) had facial dermatitis. Female patients were 9.1 times more predominant than male patients. The mean±standard deviation age of patients was 37.3±14.8years. A total of 199 (81.6%) patients demonstrated at least one positive reaction to a patch test, 66.7% of which were clinically relevant. Allergic contact dermatitis was diagnosed in 45.5% of patients. Independent factors predisposing towards facial dermatitis were female sex, having a previous history of cosmetic allergy, a positive patch test reaction to hairdressing product-related allergens, and a positive allergic reaction to preservative allergens. The prevalence of facial dermatitis was 27.4%. Almost half of all patients with facial dermatitis demonstrated ACD. Factors associated with facial ACD were female gender, a history of cosmetic allergy, and positive patch test reactions to hairdressing product-related allergens and preservatives.

Objective: Allergic contact dermatitis (ACD) is a hypersensitivity reaction which develops against substances contacting the skin. Patch tests are used for the detection the allergens that cause ACD. The most common substances that cause ACD vary based on geographic regions. In this study, detection of the most common allergens in patients who underwent patch testing with the diagnosis of ACD and comparison of the results with literature were aimed.Mateials and Methods: One hundred forty-eight patients, who underwent European standard patch test with the diagnosis of ACD in our clinic between January 2010 and June 2013, were enrolled in our study. The data about age, sex, duration of disease, occupation, the presence of atopy, localization of the lesion of the patients and patch test results were recorded retrospectively.Results: Eighty-nine females and 59 males, a total of 148 patients, were included in the study. The mean age of the patients was 35.3 ± 14.8. Positive reactions to one or more allergens were observed in forty-five (30.4%) of 148 patients who underwent patch test. The allergens that were the most common cause of positive reactions were nickel sulfate (11.5%), potassium dichromate (6.1%), cobalt chloride (4.7%), paraben mix (4.1%), thiuram mix (2.7%), neomycin sulfate (2.7%) and fragrance mix (2.7%), respectively. Conclusion: We believe that our study will contribute to the determination of contact allergens which is the most common cause of sensitization in our country

Lichen planus pigmentosus (LPP) is a common cause of facial melanosis in the dark-skinned population. At present, information on dermoscopy and patch testing in LPP is limited. To describe dermoscopic findings and study the role of patch testing in patients with LPP on the face. Facial lesions of 50 patients with LPP were studied dermoscopically, followed by histological evaluation. Patch and photopatch tests with the Indian Standard Series and Scandinavian series, respectively, and patient's own cosmetics were performed on all patients. The most common dermoscopic finding was dots and/or globules (43/50, 86%) in different patterns: hem-like (20.9%), arcuate (18.6%), incomplete reticular (39.5%), complete reticular (7%), and not otherwise specified (14%). Other patterns were exaggerated pseudoreticular pattern, accentuation of pigmentation around follicular openings, targetoid appearance, and obliteration of the pigmentary network. There were 26 relevant patch tests in 17 (34%) patients: para-phenylenediamine (n = 5), nickel (n = 3), colophony, perfume mix and fragrance mix (n = 2 each), thiuram mix and 3,3,4,5-tetrachlorosalicylanilide (n = 1 each), and patients' own products (n = 9). The only positive photopatch test was to fentichlor. No clinical or histological finding differed significantly based on patch test results. The only dermoscopic finding to be statistically associated with a positive patch test was the non-characteristic arrangement of dots/globules (P = 0.042). Dermoscopic features were not correlated with clinical features or disease duration. Implications of patch testing on the management of LPP cannot be commented upon as ours was a cross-sectional study. The present study describes the dermoscopic findings of facial lesions in LPP. Our patch test results suggest a probable role of allergens in causing LPP on the face.

Background:Allergic contact dermatitis (ACD) is a delayed type of hypersensitivity from contact with a specific allergen to which the patients has developed a specific sensitivity. The aim of the study was to evaluate the results of epicutaneous patch testing with standard series of contact allergen in patients suspected to have ACD.Methods:355 cases of ACD were included in the study. Test substances were applied on the upper part of the patient’s back, on clinically uninvolved and untreated skin. All patients were free from therapy with oral antihistamines, steroids and immunosuppressants. The patch test was removed and reaction were evaluated after 48 h and 72 h. Grading of negative (-) to positive (+ to ++++) patch test was done according to the International Contact Dermatitis Research Group. Statistical data analysis was performed by using χ2–test.Results:Of the 355 cases, 146 patients were male (41.1%) and 209 were female (58.9%). The youngest patients in the study was 16 years of age and the oldest was 67 years of age. The commonest age group affected was 41-50 years. Hands were the most common site of involvement. The occupational character of skin lesions was find in 75 (21.1%). The most common positive reactions were recorded to nickel sulphate 99 (27.8%), cobalt chloride 46 (12.9%), thimerosal 31 (8.7%), colophony 23 (6.5%), carba mix 21 (5.9%), potassium dichromate 20 (5.6%), acid chromici 19 (5.3%), fragrance mix 18 (5%), balsam of Peru 13 (3.7%), formaldehyde 9 (2.5%), and other allergens 26 (7.3%). Females were significantly more likely to show a positive response to two or more allergens (p<0.05). There was no statistically significant impact of age, occupation and duration of disease on results of patch testing (p>0.05).Conclusions:Our results indicate that nickel sulphate, cobalt chloride and thimerosal are the most common allergens responsible for induction of ACD. These findings are crucial in the treatment, long term management, an education of patients with ACD.

Contact allergy in oral disease

Elimination of allergens/topical medications causing contact dermatitis in venous eczema, which poses a significant problem in its chronicity and treatment, provides the basis for better therapeutic outcome. Our objective was to determine the pattern of contact sensitization in venous eczema patients in Himachal Pradesh (India). Thirty-four patients (M:F, 31:3) and 10 controls (M:F, 6:4) were patch tested with Indian standard series and 10 commonly used topical medicaments. Positive patch test results were seen in 50% (M:F, 16:1) of the patients. Common allergens were Fragrance mix (15%), p-phenylendiamine (15%), nickel (9%), wool alcohol (9%), chinoform (9%), balsum of Peru (5%), cobalt chloride (5%), potassium dichromate (3%), epoxy resin (3%), thiuram mix (3%) and formaldehyde (3%). Only sisomycin and miconazole among the topical medications elicited a positive patch test reaction in 3 and 5% patients, respectively. Neomycin contact sensitivity was not seen in any of the patients. One patient who had exacerbation of venous eczema following accidental application of topical diclofenac showed a positive patch test reaction to it. Patch test should be used to identify the topical agents that may be responsible for perpetuation or aggravation of eczema, especially in patients who do not improve despite adequate treatment of other underlying cause(s).

Environmental contact factors in eczema were investigated in China by clinical questionnaire and patch testing patients with a modified European standard series of allergens. 217 consecutive eczema patients were studied. Contact dermatitis (CD) was clinically diagnosed in 30% of the patients. Among the patients patch tested, 46 patients had clinically diagnosed allergic CD (ACD), 20 patients clinically had non-ACD (NACD) (including 16 cases of irritant contact dermatitis, 1 case of phototoxic contact reaction and 3 cases of asteatotic eczema) and 115 patients had clinically suspected ACD. 45 patients (98%) in the ACD group went on to have relevant patch test results. The most common ACD was from metals, fragrance materials, cosmetics and rubber materials. The most common contact allergens identified were nickel, fragrance mix, para-phenylenediamine (PPD), carba mix and thimerosal. No adverse reactions were observed to patch testing, except for pruritus in patch-test-positive patients. The positive rate of patch testing in ACD was much higher than that in NACD (98% versus 15%, P < 0.05, chi(2)-test). 60 (28%) patients had facial dermatitis (FD). Among these, 20 (33%) were confirmed as having ACD. 48 (22%) patients had hand dermatitis (HD). Among these, 7 (15%) were confirmed as having ACD. Fewer patients were confirmed as having ACD in the HD group than in the FD (15% versus 33%, P < 0.05, chi(2)-test). Although the difference was not significant, the total positivity rate in the HD group (55%) was lower than in the other groups. 65 (30%) patients had unclassified endogenous eczema (UEE). The total positive rate of patch testing in the UEE group (56%) was no different from that in the FD or HD groups. However, the relevance of positive patch tests was hard to determine in UEE. These results indicate that CD is common in eczema; relatively more patients with FD have ACD, while other factors, such as irritation, may play more of a role in HD. The total positive rate of patch testing in the UEE group was no different from that in the FD or HD groups, suggesting that patch testing should be stressed in UEE and the relevance of positive patch test results in UEE should be studied further. It is effective and safe to patch eczema patients with a modified European standard series of allergens in China.

Although contact allergy among children was previously considered to be rare, data from the past decade have shown that it is common among children and that the prevalence may be increasing. To describe the demographics of all children referred for patch testing in Denmark during 2003-2011, to examine the frequency and relevance of positive patch test reactions, and to assess the most common allergens. A retrospective analysis of the patch test data from the Danish National Database of Contact Allergy was performed. Of 2594 children and adolescents aged 1-17 years, 25.1% had one or more positive patch test reactions. The associated relevance was 66.4%. The most common sensitizers were metals, fragrances, and hair dyes. The frequency of positive patch test reactions and allergic contact dermatitis was significantly higher among girls. Allergic contact dermatitis in children is a significant clinical problem. Contact allergy should always be considered when children with recalcitrant eczema are encountered, and special attention should be paid to girls. Patch testing is important, and children may be tested with the same patch test concentrations as adults.

North American Contact Dermatitis Group patch test results for the detection of delayed-type hypersensitivity to topical allergens

Diagnosis of contact allergy (CA) to Amerchol L-101 (AL-101), a marker for lanolin allergy, is problematic. Positive patch test reactions are frequently doubtful or weakly positive and difficult to associate with clinical relevance. To gain further insight on the allergic or irritant nature of skin reactions induced by AL-101 patch test. We re-tested in a dose-response fashion, 10 subjects with AL-101 CA and performed comprehensive transcriptomic analysis (gene arrays, quantitative real-time polymerase chain reaction [qRT-PCR]) of samples of their skin reactions. Eight of the 10 CA subjects reacted positively upon re-test, whereas two did not react. Most of AL-101 positive patch tests expressed an allergy signature with strong activation of gene modules associated with adaptive immunity and downregulation of cornification pathway genes. In addition, the breadth of gene modulation correlated with the magnitude of patch test reactions and the concentration of AL-101 applied. However, we observed that some of the positive patch test reactions to AL-101 expressed no/few allergy biomarkers, suggesting the induction of an irritant skin inflammation in these samples. This study confirms that AL-101 is an allergen that can cause both contact allergy and contact irritation. Our results also highlight that molecular profiling might help to strengthen clinical diagnosis.

Background and Objectives:Allergic contact dermatitis is common in childhood as well as in adulthood. Children could be affected by numerous allergens. Allergen sources could change by region. In this study, we aimed to identify the most common allergens that cause contact sensitivity in paediatric patients in our region to make a standardized patch test series and define the ways of exposure to these allergens.Materials and Methods:Between June 2013 and January 2021, a total of 61 patients’ European baseline series patch test results were evaluated.Results:Among 61 patients, 36 (%59) were female and 25 (%41) were male. The mean age was 10.4 years. Positivity with at least one allergen was present in 39 (64%) cases. The most common allergens with positive reactions were balsam of Peru (BOP) in 11 (18%) patients, nickel in eight (13.1%) patients, and fragrance mix-1 in seven (11.4%) patients. No statically significant difference was found between patch test results and gender (P = 0.109), atopy (P = 0.774), atopic dermatitis (P = 0.662), hobby (P = 0.377) and side of lesions (P = 0.826). However, there was a significant relationship between the duration of complaints and patch test results (P = 0.007).Conclusion:The responsible allergen in paediatric patients may vary especially by region, thus this could be challenging for diagnosis. Therefore, each region should create its own specific standardized paediatric patch tests.