Background: It is unclear whether the type 2 T helper cell-specific immunosuppressive action of dupilumab interferes with patch testing.
Objectives: We sought to evaluate the reliability of patch testing on dupilumab and the contribution of allergic contact dermatitis (ACD) to complex dermatitis in patients with residual dermatitis on dupilumab.
Methods: This is a retrospective chart review of 48 patients with atopic dermatitis (AD) who were treated with dupilumab. We compare the results of patch tests performed before and after the initiation of dupilumab and the prevalence of comorbid ACD in patch-tested individuals.
Results: A minority of patch test reactions were "lost" on dupilumab (13/125; 10.4%). Five of 13 lost reactions occurred in individuals with documented immunodeficiency. Thirty-two of 35 patch-tested patients (91.4%) had comorbid ACD; 92.3% of individuals patch tested on dupilumab experienced further clinical improvement with allergen avoidance.
Limitations: This is a nonrandomized study in a small cohort of patients. The clearance of dupilumab was assessed by subjective patient reports.
Conclusions: Dupilumab does not appear to exert a dampening effect on patch test results. AD with comorbid ACD was highly prevalent and allergen avoidance resulted in significant improvement in residual dermatitis that had not resolved without dupilumab therapy.
Keywords: allergic contact dermatitis; atopic dermatitis; dermatitis; dupilumab; patch testing.
Copyright © 2019 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.