Erythema nodosum as an atypical dermatological manifestation of HTLV-1 infection: A case report and literature review.

Human T-lymphotropic virus 1 (HTLV-1) is the etiological agent of several pathologies, and some of them are not investigated, resulting in a lack of literature that impacts the correct diagnosis. Skin manifestations, such as HTLV-1-associated infectious dermatitis (IDH), are common in patients living with HTLV-1 but could not be the only one. Here, we report for the first time a patient infected with HTLV-1, without previous diagnosis of HTLV-1-related diseases, presenting erythema nodosum (EN). Given the patient's long-term asymptomatic carrier status, the emergence of EN underscores the importance of considering HTLV-1 in the differential diagnosis when encountering EN, especially in endemic regions.