Is there a paradoxical side effect? Is it a case of inefficiency? Peripheral ulcerative keratitis in a patient with rheumatoid arthritis in remission treated with tocilizumab.

Tocilizumab is a monoclonal antibody to interleukin-6 that has recently been used in rheumatoid arthritis (RA) treatment. Treatment with tocilizumab may be associated with paradoxical manifestations that are poorly understood. Patients that developed peripheral ulcerative keratitis while on tocilizumab treatment were studied in a case series. It was discovered that this could be a paradoxical side effect or ineffectiveness. Herein, we present a patient with seropositive RA who was followed for 22 years, using tocilizumab for seven years, and who developed peripheral ulcerative keratitis while in remission. Consequently, even in remission, extra-articular involvement can occur in RA patients, and medication-related paradoxical side effects can arise.