Sacroiliitis and polyneuropathy during isotretinoin treatment.

Isotretinoin, a medication for acne, has been reported to cause a variety of side effects on the musculoskeletal system. We present a case of sacroiliitis (a relatively uncommon feature) and sensorimotor demyelinating polyneuropathy, which has been reported previously in only a few cases during isotretinoin therapy. Clinical symptoms were improved after the withdrawal of isotretinoin and the follow-up electrophysiological study performed 2 years after the initial diagnosis of polyneuropathy showed mild improvement. Dermatologists are advised to be alert to symptoms of polyneuropathy and sacroiliitis during treatment with isotretinoin.