Bilateral Sacroiliitis Confirmed with Magnetic Resonance Imaging during Isotretinoin Treatment: Assessment of 11 Patients and a Review of the Literature.

In recent years, several cases pointing at sacroiliitis due to isotretinoin treatment have been reported, but a causal association remains unproven. The aim of this study was to assess the characteristics of patients in whom bilateral sacroiliitis was detected while using isotretinoin treatment for acne and to review previous sacroiliitis cases treated with isotretinoin. In total, 11 patients who were diagnosed with sacroiliitis during isotretinoin treatment were identified, and patient characteristics were noted. Patients were classified according to magnetic resonance imaging (MRI) findings. The 11 patients (3 men and 8 women) ranged in age from 16 to 37 years (mean age 24.27 years). All the 11 (100.00%) patients presented with hip pain, which in 3 (27.27%) patients started in the first month, in 3 (27.27%) in the second, in 2 (18.18%) in the third, in 2 (18.18%) in the fourth, and in 1 (9%) in the fifth. HLA-B27 (human leucocyte antigen) was negative in all cases. MRI findings confirmed mild bilateral sacroiliitis in 5 (45.45%) patients, moderate in 3 (27.27%), and severe in 2 (18.18%). Although our study included a small number of cases, it indicates a strong association between isotretinoin and sacroiliitis.