Hand and Foot Dermatitis in Patients Referred for Patch Testing: Analysis of North American Contact Dermatitis Group Data, 2001-2018.

Background: Dermatitis localized to hands (HD), feet (FD), or both hands and feet (HFD) has multiple etiologies, including atopic dermatitis, irritant contact dermatitis, and allergic contact dermatitis. Unfortunately, little is known about clinical differences between patients with HD, FD, and HFD. Objective: To characterize differences in demographics, etiology, and patch testing results among patients presenting with HD, FD, or HFD referred for patch testing. Methods: A retrospective analysis of patients patch tested by the North American Contact Dermatitis Group between 2001 and 2018. Results: Of 43,677 patients who were patch tested, 22.8% had HD, 2.9% had FD, and 3.7% had HFD. Allergic and currently relevant patch test reactions to $1 North American Contact Dermatitis Group screening allergen occurred in similar proportions in all 3 study groups. However, HD (18.0%) had higher proportions of occupationally relevant reactions than HFD (8.9%) or FD (4.0%). Nickel and fragrance mix I were in the top 5 currently relevant allergens for HD, FD, and HFD. Other top allergens, as well as allergen sources, differed between HD, FD, and HFD. Limitations: No data on HD or FD morphology or distribution. Conclusion: HD, FD, and HFD have several differences with respect to patient characteristics, etiologies, and clinically relevant allergens.