Upadacitinib shows rapid improvement in refractory acrodermatitis continua of HallopeauUpadacitinib Shows Promise for Treatment of Chronic Skin Condition

Acrodermatitis continua of Hallopeau (ACH) is a rare and chronic variant of pustular psoriasis characterized by sterile pustules, periungual inflammation, and progressive nail destruction. Due to its rarity and overlapping clinical features with other nail disorders, ACH is frequently underrecognized and remains difficult to treat, with no standardized therapeutic guidelines. Here, we report a case of long-standing, isolated ACH showing marked improvement after treatment with the selective Janus kinase 1 (JAK1) inhibitor upadacitinib. A 54-year-old man presented with a 13-year history of recurrent periungual erythema, sterile pustules, and progressive nail dystrophy affecting multiple digits. The disease was refractory to topical corticosteroids, systemic antibiotics, acitretin, and 1 year of secukinumab therapy. Following initiation of upadacitinib 15 mg daily, rapid clinical improvement was observed within 4 weeks, with reduction of subungual pustules and periungual inflammation. Nail involvement subsequently improved gradually, accompanied by nail regrowth and a decrease in the modified Nail Psoriasis Severity Index score from 66 at baseline to 16 at week 24 and 13 at month 9. No adverse or unanticipated events were observed during follow-up. This case highlights the potential role of JAK1 inhibition as an effective therapeutic strategy for refractory ACH and supports further investigation into JAK-targeted therapies in pustular psoriasis spectrum disorders.