Patch Test Results Among Older Adults: A Retrospective Analysis of the North American Contact Dermatitis Group Data (2009-2020)

Background: Allergic contact dermatitis (ACD) in older adults (OA) represents a significant health burden, but few studies examine the prevalence and characteristics of contact allergy and ACD in this population. Objective: To compare positive and clinically relevant patch test results in OA versus younger adults (YA) and children. Methods: Retrospective analysis of patch test results obtained in OA (>= 65 years), YA (19-64 years), and children (<= 18 years) by the North American Contact Dermatitis Group, 2009 to 2020. Results: Of 28,177 patients patch tested, 5366 (19.0%) were OA. OA were more likely to have a final primary diagnosis of ACD as compared with YA (50.8% vs 49.2%, P = 0.035) and children (44.6%, P < 0.0001). The primary site of dermatitis also differed by age group, with OA having a higher proportion of dermatitis affecting the trunk, scalp, anogenital region, and ''under clothing,'' and a lower proportion of dermatitis affecting the face, lips, and feet. Limitations: Retrospective design, lack of follow-up, and referral population. Conclusion: OA were as likely and were statistically even more likely to have a final primary diagnosis of ACD compared with YA and children. Anatomic site of dermatitis also differed by age group. This underscores the need for patch testing in OA when ACD is suspected.