Eruptive melanocytic nevi (EMN) are a rare phenomenon characterized by simultaneous rapid onset of multiple nevi. The condition has been described in different contexts: immunosuppression, immunosuppressive drugs, targeted therapies, bullous diseases, and chemical melanocytic stimulation. We report 3 cases of EMN following anti-TNF alpha treatment.
Case 1 - A 51-year-old female patient was receiving adalimumab for spondyloarthritis (the first treatment for this patient). A few months after the start of treatment, multiple nevi were noted on the 4 limbs, and in particular on the right palm. The patient confirmed the absence of these lesions before initiation of treatment. A diagnosis was made of adalimumab-induced EMN. Case 2 - A 49-year-old male patient was receiving etanercept for spondyloarthritis (the first biologic in this patient). Multiple small nevi developed on the trunk in the months after the start of treatment. The patient indicated that these lesions had appeared after the start of treatment. A diagnosis was made of etanercept-induced EMN. Case 3 - A 20-year-old woman with hidradenitis suppurativa was treated with infliximab. After 1.5 months, she reported the outbreak of various pigmented lesions 2-3mm in diameter on the trunk and one lesion on her right palm. The clinical diagnosis was EMN. After follow-up of 4 months to 5 years, no transformation to melanoma was noted in any of these 3 patients.
EMN remains a rare phenomenon in patients on anti-TNF alpha. These cases, associated with the description of a moderate increased risk of developing cutaneous carcinoma under anti-TNF alpha, underscore the need for dermatological follow-up and increased sun protection in patients receiving this treatment.