Bowenoid Actinic Keratosis in a Patient Receiving Abatacept for Rheumatoid Arthritis: A Case Report

We experienced a case of Bowenoid actinic keratosis on the left wrist joint in a patient receiving abatacept for rheumatoid arthritis. Simple treatment with imiquimod, initiated with the continuous use of abatacept, did not improve the lesion. Topical imiquimod successfully cured the lesion only after abatacept discontinuation in the patient. Our case suggests that abatacept has depleted the production of tumor necrosis factor-α by macrophages upon contact with imiquimod, which is a toll-like receptor 7 ligand.