LAUSR

BACKGROUND Hand eczema (HE) is a heterogeneous and burdensome disorder. OBJECTIVE To characterize the clinical characteristics, etiologies and allergen relevance in adults with HE referred for patch testing. METHODS Retrospective analysis (2000-2016) of North American Contact Dermatitis Group data (n=37,113). RESULTS Overall, 10,034 were diagnosed with HE, with differences of overlap between allergic contact, irritant contact and atopic dermatitis. Allergic contact HE fluctuated, while atopic HE steadily increased, and irritant HE decreased over time. HE was associated with higher proportions of positive patch tests (67.5% vs. 63.8%; Chi-square, P<0.0001). The five most common clinically relevant allergens were methylisothiazolinone, nickel, formaldehyde, quaternium-15 and fragrance mix I. HE was associated with significantly higher odds of positive patch test reactions and clinical relevance in 13 and 16 of the 25 most common allergens, respectively, including preservatives, metals, topical medications, and rubber accelerators. LIMITATIONS No data on HE phenotype. CONCLUSION HE in adults was associated with higher proportions of positive patch tests, with a heterogeneous profile of allergens. Patch testing remains an important tool in the evaluation of patients with HE.