Mogamulizumab‐induced granulomatous dermatitis of the scalp: a distinct entity associated with clinical response

Editor Mogamulizumab is a humanized defucosylated IgG1 j monoclonal antibody, targeting the C-C chemokine receptor 4 (CCR4). It has been approved for refractory or relapsed mycosis fungo€ıdes (MF) and S ezary syndrome (SS). Mogamulizumab-associated rash (MAR) has been reported in 44 of 184 patients (24%) in the MAVORIC phase III study. Four predominant clinical patterns have been described: folliculotropic MF-like scalp plaques with alopecia; papules and/or plaques; photoaccentuated dermatitis; morbilliform or erythrodermic dermatitis. Distinguishing MAR from disease progression may be particularly challenging. Among 25 patients with MF or SS treated with Mogamulizumab in two referral centres (Bordeaux and Reims university hospital, France), we report six patients who developed similar skin lesions on the scalp and/or periauricular areas. Detailed information is provided in Table 1. The six patients were five women and one man, aged from 57 to 71 years (median: 66), who received mogamulizumab for an MF (four cases) or an SS (two cases). All had received at least two lines of