2026 Volume 136 Issue 1 Pages 39-48
We retrospectively examined 21 cases of cutaneous paradoxical reaction under treatment with biologics. The 20 patients consisted of 9 males and 11 females, in whom biologic therapies were used to treat rheumatoid arthritis (n=4), inflammatory bowel disease (n=8), psoriasis (n=4), palmoplantar pustulosis (n=2), Behçet disease (n=1), and uveitis (n=1). Among the biologics used, TNF inhibitors were most common (n=18), followed by IL-23 inhibitors (n=2), IL-12/23 inhibitors (n=1) and IL-17 inhibitors (n=1). The developed disorders induced de novo included psoriasis/psoriasiform eruption (n=5), palmoplantar pustulosis/palmoplantar pustulosis-like eruption including extra-palmoplantar lesions (n=6), pustular psoriasis (n=2), pyoderma gangrenosum (n=1), sarcoidosis (n=1), and others (n=3). By contrast, 3 cases developed worsening of the pre-existing cutaneous manifestation. Biologics were continued in 10 cases. Among the discontinued 11 cases, biologics were switched to other biologics in 5 cases. This study was conducted in a single institution, and multicenter studies are necessary to elucidate the similarities and differences in each cutaneous paradoxical reaction by examining more number of cases.
