A Case of Adalimumab-induced Neutropenia

Abstract

We present the case of a 52-year-old male with neutropenia induced by adalimumab. He had been diagnosed with psoriasis vulgaris approximately 20 years earlier and was administered adalimumab at our hospital. The improvement rate according to the Psoriasis Area and Severity Index was 75%. Adalimumab was administered at doses of 40 mg or 80 mg per injection. Six and a half years after the start of the treatment, blood tests revealed a decreased neutrophil count. The patient had exacerbation of neutropenia eight and a half years after the start of adalimumab ; however, treatment with adalimumab was continued cautiously. As the exacerbation of neutropenia became more severe and no improvement was observed within the interval of administration, adalimumab was discontinued and ixekizumab was initiated. Ixekizumab proved to be as effective as adalimumab, and absolute blood neutrophil counts signicantly improved one month after the last administration of adalimumab. It is important to recognize that not only IL-17 inhibitors but also TNF-α inhibitors may cause neutropenia. Skin Research, 23 : 206-210, 2024