Nickel Sensitivity Rose Significantly in North America From 1994 to 2014
Investigators analyzed demographics, rates of reaction to nickel, strength of nickel reactions, and nickel allergy sources.
Nickel sensitivity has significantly increased in the last 20 years in North America, and incidence varies by demographics, according to a results from a retrospective, cross-sectional analysis published in the Journal of the American Academy of Dermatology.
Data from 44,097 patients patch-tested to gauge sensitivity to nickel (nickel sulfate hexahydrate 2.5% petrolatum) were collected from 1994 to 2014. Additional variables included sex, age, race, atopy (hay fever, eczema, asthma), dermatitis sites (≥3), and clinical relevance. Up to 3 final diagnoses and occupational relatedness were also recorded in the dataset.
Nickel sensitivity was defined as a mild (nonvesicular/erythematous/infiltrated/possible papules), strong (edematous/vesicular), or extreme (spreading/bullous/ulcerative) reaction to nickel at second reading.
Nickel sensitivity increased significantly over the study period, from 14.3% in 1994-1996 to 20.1% in 2013-2014 (P <.0001), with the overall frequency at 17.5% from 1994 to 2014 (7729/44,097 patients). Patients with nickel sensitivity were more likely to be female (relative risk [RR] 3.13; 95% CI, 2.94-3.33), ≤18 years of age (RR 1.49; 95% CI, 1.39-1.61), nonwhite, (RR 1.19; 95% CI, 1.14-1.27), and/or atopic (RR 1.09; 95% CI, 1.05-1.14).
Eczema (RR 1.10; 95% CI, 1.05-1.15) and asthma (RR 1.11; 95% CI, 1.05-1.17) were significantly associated with nickel sensitivity, though hay fever was not. Patients presenting with nickel sensitivity were significantly more likely to have a final diagnosis of allergic contact dermatitis (RR 2.31; 95% CI, 2.20-2.43).
Current clinical relevance increased significantly, from 44.1% in 1994-1996 to 51.6% in 2013-2014 (P <.0001). Occupational relatedness decreased from 7.9% in 1994-1996 to 1.9% in 2013-2014 (P <.0001). Jewelry consistently remained the most common source of nickel dermatitis, even after sources were stratified by age and sex.
Limitations to this study include the inability to follow up with the patients because of the study design and that potential sources of nickel dermatitis were limited to those with codes in the North American Contact Dermatitis Group source list.
Disclosures: Several authors acknowledge competing interests; please see original reference for a full list of authors' disclosures.
Warshaw EM, Zhang AJ, DeKoven JG, et al. Epidemiology of nickel sensitivity: retrospective cross-sectional analysis of North American Contact Dermatitis Group (NACDG) data 1994-2014 [published online October 18, 2018]. J Am Acad Dermatol. doi: 10.1016/j.jaad.2018.09.058