An Unusual Case of Psoriasiform Dermatitis Treated With Dual Biologic Therapy and Literature Review.

Previously believed to be of distinct immunopathogenesis, atopic dermatitis (AD) and psoriasis (PsO) spectrum may permit immunologic shifts to favor the opposing inflammatory states following biologic treatment. Cases of AD that developed following PsO biologics are increasingly reported in the literature. While biologic monotherapy is becoming more widely available, dual biologic therapies have been understudied. Here, we present a patient with biopsy-confirmed PsO who developed psoriasiform spongiotic dermatitis following anti-IL-17A initiation who responded to combination anti-IL-23 and anti-IL-4Ra therapy and discussed the PsO-AD immunologic spectrum and use of dual biologic therapies. J Drugs Dermatol. 2025;24(2):207-211. doi:10.36849/JDD.8382R1.