An Unusual Dermatological Side Effect of Treatment with Non-Pegylated Alpha-Interferon, Acitretin and Puva Therapy: Pigmented Macules on the Fingers in a Patient with Sézary Syndrome

Sézary syndrome is a cutaneous T-cell lymphoma characterized by the triad of erythroderma, generalized lymphadenopathy, and the presence of Sézary cells in skin, lymph nodes and peripheral blood. A 59-year-old Chinese female presented with erythroderma, palmoplantar keratoderma and enlarged right axillary and epitrochlear lymph nodes. Staging investigations showed extensive involvement of peripheral blood, bone marrow and dermatopathic lymphadenopathy. Our patient was diagnosed with Stage IVA Sézary syndrome. Darkly pigmented macules developed on her fingers after three months of interferon treatment, given in combination with acitretin and PUVA (rePUVA). Biopsy of the pigmented macule showed prominent pigmentary incontinence with numerous melanophages. Our patient responded partially to combination treatment with non-pegylated interferon, acitretin and PUVA but developed acral pigmentation. This is the first report of acral pigmentation complicating non-pegylated alpha-interferon treatment for Sézary syndrome. The putative mechanism is an increased level of alpha-melanocyte-stimulating hormone (MSH) and MSH receptor.