The different face of skin-rash induced by brentuximab vedotin

Background: Brentuximab vedotin (BV) is a targeted therapy for CD30-expressing lymphomas, including Hodgkin lymphoma (HL) and cutaneous T-cell lymphoma (CTCL). While peripheral neuropathy is the most common adverse event, BV-induced skin rashes are less frequent and not well characterized. Patients and Methods: This study analyzed the clinical and histologic features of BV-induced skin rashes over the past 5 years, focusing on patterns and severity across lymphoma types. We retrospectively reviewed cases from the Dermatology and Hematology Departments at Bologna and Ancona Universities, and we identified 20 eligible patients (13 males, 7 females, median age 59 years) with a Naranjo score ≥ 5. Six had CTCL, and 14 had systemic lymphoma. Results: Rashes appeared after a median of 3.5 BV cycles, presenting as eczematous (n = 11 patients), maculopapular (n = 3), or lichenoid (n = 6). Histology showed cytotoxic lichenoid infiltrates in lichenoid cases and spongiotic dermatitis in eczematous ones. CTCL patients experienced more severe reactions (50 % grade ≥ 3) compared to systemic lymphoma patients (36.3 %). BV was discontinued in 10 cases, while others continued with dose adjustments and corticosteroids. Conclusions: Lichenoid reactions were more common in CTCL, possibly due to BV's effects on the tumor microenvironment. Recognizing rash patterns may optimize care and minimize unnecessary treatment interruptions.