Investigation of relapse rate and factors affecting relapse after oral isotretinoin treatment in patients with acne vulgaris.

Oral isotretinoin is the most effective treatment option used in acne treatment. However, varying rates of relapse have been reported after oral isotretinoin therapy. The aim of this study was to evaluate factors that affect relapse after oral isotretinoin treatment in patients with acne. In this cross-sectional study, 212 patients with acne using 0.3-1 mg/kg/day oral isotretinoin for at least 4 months were analyzed retrospectively regarding relapse frequency and factors that affected relapse. In the study, the female-to-male ratio was 3.15, with a mean age of 23.5 ± 6.2 years. The relapse rate was found as 37.3%. The median time to relapse was 10 months. The relapse rate was higher in younger patients (age ≤ 20 years), macrocomedone-type acne, and those with residual lesions at the end of the treatment (p < 0.05 and p < 0.01, respectively). To prevent relapse in patients with acne using oral isotretinoin, it is of great importance to continue the treatment until complete clinical improvement, and extend the treatment for at least one more month regardless of the cumulative dose. Relapse may also occur with younger age and macrocomedone-type acne.