Epidemiology of nickel sensitivity: Retrospective cross-sectional analysis of North American Contact Dermatitis Group data 1994-2014.

BACKGROUND: Nickel is a common allergen. OBJECTIVE: To examine the epidemiology of nickel sensitivity in North America. METHODS: Retrospective, cross-sectional analysis of 44,097 patients patch tested by the North American Contact Dermatitis Group from 1994 to 2014. Nickel sensitivity was defined as a positive patch test for nickel. We evaluated the frequency of nickel sensitivity and patient demographics. For each positive reaction to nickel, we tabulated clinical relevance, occupational relatedness, and exposure sources. RESULTS: The average frequency of nickel sensitivity was 17.5% (1994-2014). Nickel sensitivity significantly increased over time (from 14.3% in 1994-1996 to 20.1% in 2013-2014 [P < .0001]). Nickel-sensitive patients were significantly more likely to be female, young, nonwhite, and atopic (have eczema and asthma) and/or have dermatitis affecting the face, scalp, ears, neck, arm, or trunk (P values ≤ .0474). Overall, 55.5% of reactions were currently clinically relevant; this percentage significantly increased over time (from 44.1% in 1994-1996 to 51.6% in 2013-2014 [P < .0001]). The rate of occupational relatedness was 3.7% overall, with a significant decrease over time (from 7.9% in 1994-1996 to 1.9% in 2013-2014 [P < .0001]). Jewelry was the most common source of nickel contact. LIMITATIONS: Tertiary referral population. CONCLUSIONS: Nickel allergy is of substantial public health importance in North America. The frequency of nickel sensitivity in patients referred for patch testing has significantly increased over a 20-year period.

Patients with negative patch tests: Retrospective analysis of North American Contact Dermatitis Group (NACDG) data 2001-2016.

BACKGROUND: Little is known regarding the characteristics of patients with negative patch test (NPT) results. OBJECTIVE: To characterize patients with NPT results. METHODS: Retrospective cross-sectional analysis of 34,822 patch tested patients. NPT results were defined as negative or irritant final interpretations of all North American Contact Dermatitis Group screening allergens and no relevant allergens on supplemental series. RESULTS: Almost one-third of patients (n = 10,888 [31.3%]) had NPT results. Patients with NPT results were significantly more likely to be male (P < .0001), be age 40 years or younger (P = .0054), be nonwhite (P = .0005), and have dermatitis primarily having a scattered generalized distribution (P = .0007) or primarily located on the lips (P = .0214) or eyelids (P = .0364). However, the absolute differences in age, race, and site were small and may not be clinically meaningful. Patients with NPT results were significantly less likely to have occupationally related skin disease (P < .0001). Overall, 8.3% of patients with NPT results had occupationally related skin disease, with precision production worker/machine operator (28.5%), health care worker (17.0%), and mechanic/repairer (7.5%) being the most commonly related occupations. In all, 22.9% of patients with NPT results had relevant irritants and 41.6% of irritants were occupationally related; cosmetics/health care products and soaps were common sources for both occupationally related and non-occupationally related irritants. LIMITATIONS: Retrospective cross-sectional study of tertiary referral population. CONCLUSIONS: Patients with NPT results have distinct characteristics.

Epidemiology of pediatric nickel sensitivity: Retrospective review of North American Contact Dermatitis Group (NACDG) data 1994-2014.

BACKGROUND: Nickel is a common allergen responsible for allergic contact dermatitis. OBJECTIVE: To characterize nickel sensitivity in children and compare pediatric cohorts (≤5, 6-12, and 13-18 years). METHODS: Retrospective, cross-sectional analysis of 1894 pediatric patients patch tested by the North American Contact Dermatitis Group from 1994 to 2014. We evaluated demographics, rates of reaction to nickel, strength of nickel reactions, and nickel allergy sources. RESULTS: The frequency of nickel sensitivity was 23.7%. Children with nickel sensitivity were significantly less likely to be male (P < .0001; relative risk, 0.63; 95% confidence interval, 0.52-0.75) or have a history of allergic rhinitis (P = .0017; relative risk, 0.74; 95% confidence interval, 0.61-0.90) compared with those who were not nickel sensitive. In the nickel-sensitive cohort, the relative proportion of boys declined with age (44.8% for age ≤5, 36.6% for age 6-12, and 22.6% for age 13-18 years). The most common body site distribution for all age groups sensitive to nickel was scattered/generalized, indicating widespread dermatitis. Jewelry was the most common source associated with nickel sensitivity (36.4%). LIMITATIONS: As a cross-sectional study, no long-term follow-up was available. CONCLUSIONS: Nickel sensitivity in children was common; the frequency was significantly higher in girls than in boys. Overall, sensitivity decreased with age. The most common source of nickel was jewelry.

Contact Dermatitis Associated With Nail Care Products: Retrospective Analysis of North American Contact Dermatitis Group Data, 2001-2016.

BACKGROUND: Ingredients in nail care products may lead to allergic and/or irritant contact dermatitis. OBJECTIVE: The aims of this study were to determine frequency of contact dermatitis associated with nail care products, characterize associated body sites, and describe causative allergens. METHODS: A retrospective analysis was conducted with the North American Contact Dermatitis Group data between 2001 and 2016. RESULTS: Of the 38,775 patients tested, 769 (2.0%) had: 1) more than 1 allergic patch test reaction associated with a nail care product (n = 746), 2) irritant contact dermatitis associated with a nail care product (n = 14), or 3) both (n = 9). Primary body sites included the face (43.0%) and hands (27.6%). The top 5 allergens were (2-hydroxyethyl methacrylate (273/482, 56.6%), methyl methacrylate (210/755, 27.8%), ethyl acrylate (190/755, 25.2%), ethyl-2-cyanoacrylate (12/175, 6.9%) and tosylamide (273/755, 36.2%). Frequency of allergy to 2-hydroxyethyl methacrylate (P = 0.0069) and ethyl acrylate (P = 0.0024) significantly increased over the study period, whereas allergy secondary to tosylamide significantly decreased (P < 0.0001). CONCLUSIONS: As long-lasting nail techniques become widespread, the prevalence of contact dermatitis to nail care products is expected to increase. Almost one-fifth of nail care product-associated allergens would have been missed without additional screening allergens beyond the North American Contact Dermatitis Group series, underscoring the need for testing to a broad array of allergens.

Evaluation of Patch Test Findings in Patients With Anogenital Dermatitis.

Importance: Contact dermatitis in the anogenital area is associated with sleep disturbance and dyspareunia and can profoundly affect quality of life. The literature on anogenital contact dermatitis and culprit allergens is limited. The last large-scale study on common, relevant allergens in patients with anogenital dermatitis was published in 2008. Objectives: To characterize patients with anogenital dermatitis referred for patch testing by the North American Contact Dermatitis Group, to identify common allergens, and to explore sex-associated differences between anogenital dermatitis and allergens. Design, Setting, and Participants: A retrospective, cross-sectional analysis was conducted of the North American Contact Dermatitis Group database among 28 481 patients who underwent patch testing from January 1, 2005, to December 31, 2016, at outpatient referral clinics in the United States and Canada. Exposure: Patch testing for allergens. Main Outcomes and Measures: Currently relevant allergic patch test reactions in patients with anogenital dermatitis. Results: Of 28 481 patients tested during the study period, 832 patients (336 men and 496 women; mean [SD] age, 50.1 [26.5] years) had anogenital involvement and 449 patients (177 men and 272 women; mean [SD] age, 49.6 [17.4] years) had anogenital dermatitis only. Compared with those without anogenital involvement, there were significantly more male patients in the group with anogenital dermatitis (177 [39.4%] vs 8857 of 27 649 [32.0%]; relative risk, 1.37; 95% CI, 1.14-1.66; P < .001). In the group with anogenital involvement, female patients were significantly less likely than male patients to have allergic contact dermatitis as a final diagnosis (130 [47.8%] vs 107 [60.5%]; relative risk, 0.78; 95% CI, 0.64-0.94; P = .01), whereas a final diagnosis of other dermatoses (eg, lichen planus, lichen sclerosus, or lichen simplex chronicus) was more frequent for female patients than for male patients (67 [24.6%] vs 28 [15.8%]; relative risk, 1.54; 95% CI, 1.02-2.31; P = .03). Of the 449 patients in the group with anogenital involvement only, 227 (50.6%) had 1 or more relevant reaction with patch testing. Allergens that were statistically significantly more common in patients with anogenital involvement compared with those without anogenital involvement included medicaments such as dibucaine (10 of 250 patients tested [4.0%] vs 32 of 17 494 patients tested [0.2%]; relative risk, 22.74; 95% CI, 11.05-46.78; P < .001) and preservatives such as methylchloroisothiazolinone and methylisothiazolinone (30 of 449 patients tested [6.7%] vs 1143 of 27 599 patients tested [4.1%]; relative risk, 1.61; 95% CI, 1.14-2.41; P = .008). A total of 152 patients met the definition for anogenital allergic contact dermatitis, which is defined as anogenital involvement only, allergic contact dermatitis as the only diagnosis, and 1 or more positive reaction of current clinical relevance. Conclusions and Relevance: For patients with anogenital involvement only who were referred for patch testing, male patients were more likely to have allergic contact dermatitis, whereas female patients were more likely to have other dermatoses. Common allergens or sources consisted of those likely to contact the anogenital area. For individuals with anogenital involvement suspected of having allergic contact dermatitis, reactions to preservatives, fragrances, medications (particularly topical anesthetics), and topical corticosteroids should be tested.

Facial Dermatitis in Male Patients Referred for Patch Testing: Retrospective Analysis of North American Contact Dermatitis Group Data, 1994 to 2016.

Importance: Facial dermatitis in women is well characterized. However, recent shifts in the men's grooming industry may have important implications for male facial dermatitis. Objective: To characterize male patients with facial dermatitis. Design, Setting, and Participants: A 22-year retrospective cross-sectional analysis (1994-2016) of North American Contact Dermatitis Group (NACDG) data, including 50 507 patients who underwent patch testing by a group of dermatology board-certified patch test experts at multiple centers was carried out. Facial dermatitis was defined as involvement of the eyes, eyelids, lips, nose, or face (not otherwise specified). Main Outcomes and Measures: The main outcome was to compare characteristics (including demographics and allergens) between male patients with facial dermatitis (MFD) and those without facial dermatitis (MNoFD) using statistical analysis (relative risk, CIs). Secondary outcomes included sources of allergic and irritant contact dermatitis and, for occupationally related cases, specific occupations and industries in MFD. Results: Overall, 1332 male patients (8.0%) were included in the MFD group and 13 732 male patients (82.0%) were included in MNoFD. The mean (SD) age of participants was 47 (17.2) years in the MFD group and 50 (17.6) years in the MNoFD group. The most common facial sites were face (not otherwise specified, 817 [48.9%]), eyelids (392 [23.5%]), and lips (210 [12.6%]). Participants in the MFD group were significantly younger than MNoFD (mean age, 47 vs 50 years; P < .001). Those in the MFD group were less likely to be white (relative risk [RR], 0.92; 95% CI, -0.90 to 0.95) or have occupationally related skin disease (RR, 0.49; 95% CI, -0.42 to 0.58; P < .001) than MNoFD. The most common allergens that were associated with clinically relevant reactions among MFD included methylisothiazolinone (n = 113; 9.9%), fragrance mix I (n = 27; 8.5%), and balsam of Peru (n = 90; 6.8%). Compared with MNoFD, MFD were more likely to react to use of dimethylaminopropylamine (RR, 2.49; 95% CI, -1.42 to 4.37]) and paraphenylenediamine (RR, 1.43; 95% CI, -1.00 to 2.04; P < .001). Overall, 60.5% of NACDG allergen sources were personal care products. Conclusions and Relevance: Although many allergens were similar in both groups, MFD were more likely to react to use of dimethylaminopropylamine and paraphenylenediamine, presumably owing to their higher prevalence in hair products. Most sources of allergic and irritant contact dermatitis in MFD were personal care products. This study provides insight into the risks and exposures of the increasing number of grooming products used by male dermatology patients. This will enable clinicians to better identify male patients who would benefit from patch testing and treat those with facial dermatitis.

Occupationally Related Nickel Reactions: A Retrospective Analysis of the North American Contact Dermatitis Group Data 1998-2016.

BACKGROUND: The epidemiology of nickel allergy in occupational settings is not well understood. OBJECTIVE: The aim of the study was to characterize occupationally related nickel allergy (ORNA). METHODS: This is a retrospective cross-sectional analysis of 44,378 patients patch tested by the North American Contact Dermatitis Group from 1998 to 2016. Characteristics of individuals with ORNA were compared with those with non-ORNA (NORNA). RESULTS: A total of 7928 (18.2%) individuals were positive to nickel sulfate 2.5%. Two hundred sixty-eight (3.4%) had ORNA. As compared with NORNA, ORNA was statistically associated with the male sex (41.0% vs 12.9%, P < 0.001), a diagnosis of irritant contact dermatitis (22.4% vs 12.0%, P < 0.001), and no history of eczema (81.7% vs 75.7%, P = 0.0217). The most common sites of ORNA dermatitis were hand (39.9%) and arm (18.1%), which were significantly more common than in NORNA (P < 0.0001). Sixteen industry categories and 22 occupation categories were identified for ORNA; the most common industries were durable goods manufacturing (24.6%) and personal services (15.7%), and the most frequent occupations were hairdressers/cosmetologists/barbers (14.3%), machine operators (9.3%), and health care workers (7.1%). Overall 30% of ORNA occupations were in metalworking. Of 215 ORNA sources identified, instruments/phones/other equipment (16.3%), vehicles/machinery (15.8%), and tools (15.3%) were the most common. CONCLUSIONS: Occupational nickel allergy is distinct from nonoccupational nickel allergy.

Contact Dermatitis Associated With Skin Cleansers: Retrospective Analysis of North American Contact Dermatitis Group Data 2000-2014.

BACKGROUND: There is limited information regarding contact dermatitis (CD) associated with skin cleansers (SCs). OBJECTIVE: The aim of the study was to evaluate the prevalence of allergic patch test (APT) reactions and irritant CD (ICD) associated with SCs. METHODS: A retrospective cross-sectional analysis was performed using North American Contact Dermatitis Group data, 2000-2014. RESULTS: Of 32,945 tested patients, 1069 (3.24%) had either APT reaction or ICD associated with SCs. Of these, 692 (64.7%) had APT reaction only, 350 (32.7%) had ICD only, and 27 (2.5%) had both. Individuals with APT reaction and/or ICD were more likely to have occupationally related skin disease (relative risk [RR] = 3.8 [95% confidence interval {CI} = 3.3-4.5] for APT reaction and 10.0 [95% CI = 8.2-12.2] for ICD, respectively, P < 0.0001). As compared with those without APT reaction to SC, individuals with APT reaction had significantly higher frequencies of hand (RR = 2.4 [95% CI = 2.1-2.7]) and arm dermatitis (RR = 1.3 [95% CI = 1.1-1.6], P ≤ 0.001). Irritant CD was strongly associated with hand dermatitis (RR = 6.2 [95% CI = 5.2-7.3], P < 0.0001). More than 50 allergens were associated with SCs including quaternium-15 (11.2%), cocamidopropyl betaine (9.5%), methylchloroisothiazolinone/methylisothiazolinone (8.4%), coconut diethanolamide (7.9%), fragrance mix I (7.7%), Myroxylon pereirae (5.9%), 4-chloro-3,5-xylenol (5.8%), amidoamine (5.5%), and formaldehyde (4.4%). CONCLUSIONS: Many allergens, especially preservatives and surfactants, were associated with SCs. Most cases involved the hands and were occupationally related.

Piercing and Metal Sensitivity: Extended Analysis of the North American Contact Dermatitis Group Data, 2007-2014.

BACKGROUND: Body piercing provides a unique route of metal exposure. OBJECTIVE: The aim of this study was to update previous analyses using the North American Contact Dermatitis Group data comparing pierced and unpierced individuals. METHODS: This was a retrospective cross-sectional analysis of 17,912 patients patch tested by the North American Contact Dermatitis Group from 2007 to 2014 for demographics, positive reactions to metals (nickel, cobalt, chromium), and detailed analysis of nickel reactions by age, sex, and source of exposure. RESULTS: Piercing was significantly associated with female sex, being older than 18 years, and atopy (P < 0.003). Nickel sensitivity was associated with 1 or more piercing for men and women combined (P < 0.0001; relative risk [RR], 2.54; 95% confidence interval [CI], 2.35-2.75), although this association was stronger for men (RR, 2.21; 95% CI, 1.77-2.76) than women (RR, 1.47; 95% CI, 1.31-1.65). The frequency of positivity to nickel increased with number of piercings (14.3% for 1 piercing to 34.0% with ≥5 piercings). Piercing was not significantly associated with cobalt sensitivity alone (P = 0.8992) and was negatively associated with chromium sensitivity (P < 0.0001). Jewelry was the most common source of allergic reactions to nickel irrespective of sex or pierced status. CONCLUSIONS: Nickel sensitivity was significantly associated with piercing in both men and women. Jewelry was the most common source.