Review of Herpes Zoster Occurrence in Patients With Atopic Dermatitis Treated With <scp>JAK</scp> Inhibitors

Atopic dermatitis (AD) is a chronic inflammatory skin disease that markedly impairs quality of life. Janus kinase inhibitors (upadacitinib, abrocitinib, and baricitinib) are effective therapies for moderate-to-severe AD but are associated with viral reactivation, particularly herpes zoster (HZ), due to immunosuppressive effects on interferon signaling and natural killer cell activity. The objective of this study was to systematically evaluate the risk of HZ among AD patients treated with JAK inhibitors (JAKis), identify key risk factors, and assess the clinical outcomes and management of HZ in this population. A systematic review of PubMed, Embase, and the Cochrane Library evaluated HZ risk in adolescents and adults with moderate-to-severe AD treated with JAK. Searches followed PRISMA guidelines using MeSH and EMTREE terms. The protocol was registered in PROSPERO (CRD420251070483). Eligible English-language studies included randomized trials, cohort studies, pooled safety analyses, and case series with ≥ 5 participants; reviews, case reports, and pediatric, animal, or in vitro studies were excluded. Data extraction was performed independently by two reviewers. The certainty of evidence was assessed using the GRADE approach. Eleven studies were included. The risk of HZ incidence appears higher in older patients. In some cases, the risk correlates with higher doses of JAK inhibitors, and a trend toward increased HZ events has been observed in Asian populations. HZ is a relevant but generally manageable adverse event in AD patients on JAKis. Risk stratification by age, dose, and comorbidities is advised. Ongoing real-world monitoring is crucial for optimizing outcomes.