American Contact Dermatitis Group Data Research Articles

Positive Patch-Test Reactions to Iodopropynyl Butylcarbamate: Retrospective Analysis of North American Contact Dermatitis Group Data, from 1998 to 2008

iodopropynyl butylcarbamate (IPBC), a commonly used preservative, is found in industrial and personal care products. to evaluate prevalence, clinical relevance, occupational relationship, and sources of positive reactions to IPBC in patients in North America. the North American Contact Dermatitis Group (NACDG) tested IPBC 0.1% and/or 0.5% in petrolatum (pet) between 1998 and 2008. Two patient groups of interest were defined, based on patch-test reactions to IPBC: weak (+) reactors and strong (++ or +++) reactors. Patient characteristics, site(s) of dermatitis, sources of positive reactions, clinical relevance, and occupational relevance to IPBC were tabulated. of the 25,321 patients tested, there were 226 (0.9%) weak reactors and 67 (0.3%) strong reactors. For IPBC-positive patients, the most frequent sites of dermatitis were scattered generalized distribution, hands, and arms. The majority (> 50%) of currently relevant reactions were to personal care products, and most reactions (> 90%) were not related to occupation. Only four of the strong reactors had definite clinical relevance (positive use-test reaction or positive patch-test reaction to a product containing IPBC). The frequency of positive reactions increased (0.2% vs 1.5%) when the higher concentration of IPBC was utilized, but most (> 64%) were weak reactions, of which some were likely irritant. allergy to IPBC is relatively uncommon. When clinically relevant, personal care products were the most likely allergen source. Because IPBC is a marginal irritant, caution should be utilized when testing with higher concentrations of IPBC (≥ 0.5% pet) and when interpreting weak (+) reactions. Verification of clinical relevance by use test or repeat patch testing or both is also important.

The value of patch testing patients with a scattered generalized distribution of dermatitis: Retrospective cross-sectional analyses of North American Contact Dermatitis Group data, 2001 to 2004

The value of patch testing patients with a scattered generalized distribution of dermatitis: Retrospective cross-sectional analyses of North American Contact Dermatitis Group data, 2001 to 2004

Contact Allergy in Children Referred for Patch Testing

To determine the frequency of positive and relevant patch tests in children referred for patch testing in North America; to compare results of patch testing children and adults; and to compare our results with international data on contact allergy in children. Retrospective cross-sectional analyses of North American Contact Dermatitis Group (NACDG) data from January 1, 2001, through December 31, 2004. Patch test reactions for allergens that were positive and considered of clinical importance to the patient's eczematous problem were defined as being of current or past relevance. Clinical patch test data from 13 NACDG members, primarily a referral population. The pediatric population (hereafter referred to as "children") was defined as patients aged 0 to 18 years (n = 391). Patients 19 years and older constituted the comparison adult group (n = 9670). The frequency of positive patch test reactions and number of relevant ones. Secondary measures included the association of atopic markers, frequency of irritant reactions, and sources of relevant supplementary allergens. No significant difference in the overall frequency of at least 1 relevant positive patch test reaction was noted in children (51.2%) compared with adults (54.1%). The most frequent positive reactions in children were to nickel (28.3%), cobalt chloride (17.9%), thimerosal (15.3%), neomycin sulfate (8.0%), gold sodium thiosulfate (7.7%), and fragrance mix (5.1%). For children aged 0 to 18 the most frequent relevant positive reactions were to nickel sulfate (26.0%), cobalt (12.4%), neomycin (4.4%), fragrance mix (4.1%), gold (3.6%), and quaternium 15 (3.6%). The frequency of irritant reactions in adults and children was similar. Of the children with a relevant positive reaction, 34.0% had atopic dermatitis included as one of their final diagnoses, compared with 11.2% of adults (P < .001). Fifteen percent and 39% of children had relevant allergens not included in the NACDG series and a commercially available skin patch test (T.R.U.E. TEST [thin-layer rapid use epicutaneous test], panel 1.1 and 2.1; Allerderm, Phoenix, Arizona), respectively. Adults and children in this group are equally likely to have allergic contact dermatitis; frequency of relevant allergen reactions differs.

Contact Dermatitis Associated with Food: Retrospective Cross-Sectional Analysis of North American Contact Dermatitis Group Data, 2001-2004

Allergic and irritant contact dermatitis to food is likely underreported. To characterize relevant allergens and irritants associated with food in patients referred to the North American Contact Dermatitis Group (NACDG) for patch testing. Retrospective analysis of cross-sectional data from the NACDG from 2001 to 2004. Of 10,061 patch-tested patients, 109 (1.1%) had a total of 122 reactions associated with food. Approximately two-thirds of patients (66%) were female, and one-third (36%) were atopic. The hands were the most common sites of dermatitis (36.7%). There were 78 currently relevant (definite, probable, or possible) allergic reactions to NACDG standard series allergens with a food source; the most common allergen was nickel (48.7%), followed by Myroxilon pereirae (balsam of Peru) (20.6%) and propylene glycol (6.4%). Twenty allergic reactions to non-NACDG standard allergens and 24 relevant food irritants were also identified. Overall, 21% (25 of 122) of all reactions (irritant and allergic) were occupation related; the majority of these (17 of 25) were relevant irritant reactions. Cooks were the most commonly affected occupational group (40%). In this limited data set, nickel, Myroxilon pereirae, and propylene glycol were the most common allergens identified with a food source. Of food-related occupational disease, irritation was more common than allergy.

The value of patch testing patients with a scattered generalized distribution of dermatitis: Retrospective cross-sectional analyses of North American Contact Dermatitis Group data, 2001 to 2004

A scattered generalized distribution (SGD) of dermatitis is a challenging problem; patch testing is a strategy for evaluating allergic contact dermatitis as a relevant factor. We sought to analyze patient characteristics and most frequently relevant positive allergens in patients presenting for patch testing with SGD. We conducted retrospective cross-sectional analysis of North American Contact Dermatitis Group 2001 to 2004 data. Patients with SGD were compared with patients without SGD. Of 10,061 patients, 14.9% (n = 1497) had only a SGD. Men and patients with a history of atopic eczema were more likely to have dermatitis in a SGD (P < .001). Preservatives, fragrances, propylene glycol, cocamidopropyl betaine, ethyleneurea melamine formaldehyde, tixocortol pivalate, and budesonide were among the more frequently relevant positive allergens. Top allergen sources included cosmetics/beauty preparations/skin and health care products, clothing, and topical corticoids. This was a retrospective analysis of patch-tested patients with SGD suspected to have allergy. A total of 49% of patients with SGD had at least one relevant positive allergen, thus demonstrating the benefit of patch testing these patients.

Patch-Test Reactions to Topical Anesthetics: Retrospective Analysis of Cross-Sectional Data, 2001 to 2004

Allergy to topical anesthetics is not uncommon. The cross-reactivity among topical anesthetics and the screening value of benzocaine alone are not well understood. The goals for this study were: (1) to evaluate the frequency and pattern of allergic patch-test reactions to topical anesthetics, using North American Contact Dermatitis Group (NACDG) data, and (2) to compare these results to allergen frequencies from other published studies. The NACDG patch-tested 10,061 patients between 2001 and 2004. In this analysis patients were included who had positive patch-test reactions to one or more of the following: benzocaine, lidocaine, dibucaine, tetracaine, and prilocaine. Of patch-tested patients, 344 (3.4%) had an allergic reaction to at least one anesthetic. Of those, 320 (93.0%) had an allergic reaction to only one topical anesthetic. Overall, reactions to benzocaine (50.0%, 172 of 344) were most prevalent, followed by reactions to dibucaine (27.9%, 96 of 344); however, reactions to dibucaine were significantly more frequent in Canada than in the United States (relative risk [RR], 2.31; 95% confidence interval [CI], 1.67-3.20; p < .0001). Of patients reacting to more than one anesthetic, most (79%, 19 of 24) reacted to both an amide and an ester. Of the topical anesthetics tested, benzocaine was the most frequent allergen overall. Over 50% of allergic reactions to topical anesthetics in this study would have been missed had benzocaine been used as a single screening agent. Cross-reactivity patterns were not consistent with structural groups.

Contact dermatitis of the hands: Cross-sectional analyses of North American Contact Dermatitis Group Data, 1994-2004

Hand dermatitis, including irritant and allergic contact dermatitis (ACD), is common. To evaluate allergens, relevant irritants, sources and occupations associated with hand contact dermatitis using North American Contact Dermatitis Group (NACDG) data. A cross-sectional analysis of 22,025 patients patch tested between 1994 and 2004. Hand involvement was found in 6953 patients; 959 had ACD as the only diagnosis. In these 959 patients, the 12 most frequent relevant allergens were quaternium-15 (16.5%), formaldehyde (13.0%), nickel sulfate (12.2%), fragrance mix (11.3%), thiuram mix (10.2%), balsam of Peru (9.6%), carba mix (7.8%), neomycin sulfate (7.7%), bacitracin (7.4%), methyldibromoglutaronitrile/phenoxyethanol 2.0% (7.4%), cobalt chloride (6.5%), and methyldibromoglutaronitrile/phenoxyethanol 2.5% (6.3%). Rubber allergens were most commonly associated with occupation. One third of patients with hand ACD had identifiable relevant irritants. Cross-sectional analyses prevent evaluation of causal associations. In NACDG patients with hand ACD, the most common allergens included preservatives, metals, fragrances, topical antibiotics, and rubber additives.