Background: Daclizumab is a humanized monoclonal antibody against the D-subunit (CD25) of the high-affinity interleukin (IL)–2 receptor, used for the treatment of relapsing-remitting multiple sclerosis with a large spectrum of cutaneous adverse reactions. Case presentation: We present the case of a middle-aged man treated with daclizumab for multiple sclerosis, who developed skin reactions difficult to evaluate. A 4 mm punch-biopsy was taken from the plantar area. Histological examination of the biopsy revealed hyperkeratosis and acanthosis but no parakeratosis, while a discrete inflammatory infiltrate was noticed around vessels in the dermis. Treatment with fluconazole 50 mg/day for 10 days, moisturizers, and grade I topical steroids was followed by slight improvement of the clinical picture. Treatment with daclizumab was not discontinued. Conclusion: The clinical efficacy and side effects of daclizumab have to be reported and confirmed in clinical practice in the following years. Any clinical report can contribute to validate the efficacy and risk of the drug’s administration. Any type of adverse skin reaction must be reported for clarifying the diagnosis.
