Patch testing and aeroallergen intradermal testing in suspected allergic contact dermatitis, unclassified endogenous eczema and non-atopic chronic urticaria

The purpose of this study was to investigate the significance of contact allergen and aeroallergen sensitization in suspected allergic contact dermatitis (ACD), unclassified endogenous eczema (UEE) and non‐atopic chronic urticaria (NACU). 63 cases of suspected ACD, 140 cases of suspected UEE and 21 cases of suspected NACU were patch tested with the standard series of Beijing Medical University and, if available, suspected materials as is. 22 such cases of ACD, 104 such cases of UEE and 42 such cases of NACU were intradermally tested with common aeroallergens. Patients with non‐allergic skin disease served as controls. 85.7% of the suspected ACD patients, 57.9% of the suspected UEE patients and 52.4% of the suspected NACU patients were positive on patch testing, and the results in 81.0% of the suspected ACD patients and 23.6% of the suspected UEE patients were considered relevant. No patch test reactions in the NACU patients were considered relevant. 27.1% of the suspected UEE patients, 41.3% of the suspected ACD patients and 14.3% of the suspected NACU patients reacted to 2 or more contact allergens. High positive rates on aeroallergen intradermal testing were also found in suspected NACU (69.0%), UEE (49.0%) and ACD (59.1%) patients. These results support the conclusions that patients with allergic skin diseases will develop multiple sensitization, and that early detection and avoidance of sensitizing allergens is necessary. The exact rôle of aeroallergen sensitization in these diseases needs further study.     

Intradermal testing in the diagnosis of allergic contact dermatitis

Contact hypersensitivity may be diagnosed with patch testing or intradermal testing. Although these methods have been used earlier in parallel, patch testing has gradually become the only method in routine diagnosis of contact allergy. Recent findings in corticosteroid contact hypersensitivity have shown that patch testing is not always an optimal method, especially when poor penetrants are used. Therefore, a reappraisal of intradermal testing is presented, based on the literature. Studies employing both patch and intradermal testing are reviewed and the advantages and disadvantages of intradermal tests as compared to patch tests in contact allergy diagnostics are discussed. We find that it might be worthwile to evaluate whether contact allergy to compounds other than corticosteroids may be easier to detect with intradermal than patch test.     

Patch testing for allergic contact dermatitis to cigarettes: Smoked/unsmoked components and formaldehyde factors

A patient with hand dermatitis reported that switching her smoking hand resulted in reduced symptoms. When allergy to cigarettes is suspected the literature supports standard allergy testing as well as testing the individual components of cigarettes. Initial standard patch testing revealed an allergy to formaldehyde and the formaldehyde releasing agent, quaternium‐15. The patient did not react to her usual roll‐your‐own cigarette components but reacted to the smoked filter paper of a particular brand of cigarette she frequently borrowed from a friend. Possible explanations include either a variation of ingredients between cigarettes that alters the formaldehyde concentration or another unidentified allergen in the branded cigarette causing allergic contact dermatitis.     

Contact allergy and allergic contact dermatitis in children - a review of current data

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.     

Occupational dermatoses in health care workers evaluated for suspected allergic contact dermatitis

Background:  Occupational skin diseases, including allergic contact dermatitis (ACD), irritant contact dermatitis, and allergic contact urticaria (ACU), occur commonly among health care workers (HCWs).
Purpose:  To evaluate the aetiology of the various skin diseases afflicting HCWs evaluated for suspicion of ACD and/or ACU and to identify the most common allergens among HCWs found to have ACD and/or ACU.
Methods:  A total of 1434 patients underwent patch testing. The demographic data and most common allergens for HCWs ( n  = 100) and non-HCWS ( n  = 1334) were compared.
Results:  HCWs were statistically more likely than non-HCWS to be female, have hand dermatitis, and have a history of atopy. HCWs were also more likely to have work-related ACD especially to quaternium-15, thiuram, carba mix, glutaraldehyde and benzalkonium chloride, and to have ACU to latex.
Limitations:  This study was retrospective and is subject to the resultant biases of all such investigations. Only patients suspected of having ACD and who underwent patch testing are included in our database. The prevalence of ACD and ACU is likely to be higher than that seen in the general HCW population.
Conclusions:  Our results underscore the importance of thoroughly evaluating HCWs for ACD and ACU with the use of expanded standard allergen series and prick or radioallergosorbent testing to latex.     

Influence of skin peeling procedure in allergic contact dermatitis

Background:  The prevalence of allergic contact dermatitis in patients who have previously undergone skin peeling has been rarely studied.
Objectives:  We compared the frequency of positive patch test (PT) reactions in a patient group with a history of peeling, to that of a control group with no history of peeling.
Patients/Methods:  The Korean standard series and cosmetic series were performed on a total of 262 patients. 62 patients had previously undergone peeling and 200 patients did not.
Results:  The frequency of positive PT reactions on Korean standard series was significantly higher in the peeling group compared with that of the control group ( P  < 0.05, chi-square test). However, the most commonly identified allergens were mostly cosmetic-unrelated allergens. The frequency of positive PT reactions on cosmetic series in the peeling group was higher than that of the control group, but lacked statistical significance. The frequency (%) of positive PT reactions on cosmetic series in the high-frequency peel group was higher than that of the low-frequency group, but lacked statistical significance.
Conclusion:  It appears peeling may not generally affect the development of contact sensitization. Further work is required focusing on the large-scale prospective studies by performing a PT before and after peeling.     

Patch testing in children with hand eczema. A 5-year multicentre study in Spain

Background. Hand eczema is common in children, but affected children are seldom patch tested. Relatively few studies have assessed patch testing in the paediatric population, and none has specifically evaluated its use in hand eczema in children. Objectives. The aim of this study was to determine the prevalence of contact allergy in children with hand eczema, and to identify the most frequent allergens and their relevance. Material and methods. We performed a 5‐year retrospective study of children (aged 0–15 years) with hand eczema tested with the Spanish baseline series at the Dermatology Departments of 11 Spanish hospitals. Results. During the study period, 11 729 patients were patch tested, of whom 480 were children. Hand eczema was present in 111 (23.1%) of the children and in 3437 (30.5%) of the adults. Of the children with hand eczema, 46.8% had at least one positive reaction in the patch tests. Current relevance was found for 78% of the allergens detected. The most common allergens were nickel sulfate, methylchloroisothiazolinone/methylisothiazolinone, and fragrance mix I. Allergic contact dermatitis was the most frequent diagnosis (36%), followed by atopic dermatitis. Conclusions. Allergic contact dermatitis was the most usual diagnosis in our series of children with hand eczema. We recommend patch testing of all children with chronic hand eczema, as is already performed in adults.     

Hidden risks in toys: A systematic review of pediatric toy contact dermatitis

Toys are a reflection of the compounds used frequently in manufacturing. Allergic contact dermatitis to potties, metal toys, and children's jewelry is well known, however, there is a broad range of skin risks in toys. With the objective to identify and publicize the associated risk of contact dermatitis in children's toys, we have searched the PubMed database from creation to September 9, 2019. Studies were eligible if they reported a new case of contact dermatitis secondary to interaction with a toy in patients from birth to 18 years of age. A toy was defined as something children interact with for entertainment during leisure time. In this review of the PubMed database we filtered by age and language which may have prevented us from detecting cases in adults that could be extrapolated to children. In addition, several articles were excluded based on title alone. A total of 1312 articles were identified and reviewed manually for inclusion criteria. Review of the articles found 25 original articles for consideration. Several toys were found to be associated with contact dermatitis. These included electronics, toy cars, costume jewelry, bicycles, sqwish balls, slime, Play-Doh, and plasticine. Electronics such as video game controllers, cellphones, iPads, and computers were implicated. In conclusion, there is still an unmet need for observation of this segment of industry for labeling of contents and ongoing surveillance.     

Patch testing for permanent-press allergic contact dermatitis

During the decade of the 90s, 24 cases of permanent-press textile-resin contact dermatitis were identified. The most common allergen associated with these cases was dimethylol propylene urea (DMPU). Although previous reports had suggested ethylene urea melamine formaldehyde resin (EUMF) or dimethylol dihydroxy ethylene urea (DMDHEU) as the most appropriate test materials for this type of contact dermatitis, we could not confirm EUMF as appropriate but, with some limitations, can support DMDHEU due to its widespread and continued use. DMPU has been withdrawn from the marketplace and replaced with what may be less reactive materials. In this study, we also observed discordance between EUMF patch tests in the range of 30%, which is consistent with previous reports about the biovariability of patch test results.     

Allergens responsible for allergic contact dermatitis among children: a systematic review and meta-analysis

Background. Multiple studies have evaluated diverse allergens in paediatric populations. Consensus is still lacking on which allergens are most commonly implicated in allergic contact dermatitis. Objectives. To evaluate the proportion of positive reactions for allergens tested in children and to identify allergens with positive reactions in at least 1% of them. Methods. This was a systematic review of studies in PubMed (1966–2010) investigating allergens in at least 100 enrolled children. Proportions of positive reactions for each allergen were combined with random effects models across studies. Results. We included 49 studies with available data on 170 allergens. Each study tested a median of two allergens. Among the 94 allergens evaluated by at least two studies, 58 had estimates of positive reactions of at least 1% by random effects calculations, and for 21 of them the 95% confidence interval ensured that the proportion of positive reactions was at least 1%. The top five allergens tested by at least two studies included nickel sulfate, ammonium persulfate, gold sodium thiosulfate, thimerosal, and toluene‐2,5‐diamine (p‐toluenediamine). For most allergens, the proportion of positive reactions was higher in studies published after 1995 than in earlier studies (p = 0.0065). Conclusions. This meta‐analysis offers guidance on which allergens are most prevalent in the paediatric population and should have priority for inclusion in standardized allergen series.     

Patch testing and contact allergens in Ethiopia – results of 514 contact dermatitis patients using the European baseline series

Background: Patch testing is essential to diagnose allergic contact dermatitis. Dermatologists in many countries use a baseline (standard) series covering the major allergens responsible for allergic contact dermatitis in their population, with the addition of relevant allergens for the individual patient. However, a baseline series has not yet been developed for Ethiopia. Our objective in this study is to identify common contact allergens to form the basis of a future baseline series in Ethiopia. Methodology: We patch tested 514 subjects with dermatitis according to the recommended procedure using the European baseline series for 1 year. Results: 52.7% of the tested subjects showed positive reaction for at least one allergen tested. The top five contact allergens identified were nickel sulfate, fragrance mix I, cobalt chloride, p‐tert‐butylphenolformaldehyde (PTBP) resin and potassium dichromate. Positive reactions to nickel and PTBP were commoner in females. PTBP positivity was strongly associated with foot eczema. Positive test reactions were commoner in cement workers, notably to potassium dichromate, which was also a commoner allergen in patients presenting with hand dermatitis. There were no reactions to several allergens, including neomycin, benzocaine, budesonide, primin and quaternium‐15. Conclusion: Comparable patch test results with other countries have been shown and the European baseline series can be used as a baseline series in Ethiopia with some modification.