 The goal of this study is to enroll 250 participants that have joined the MURDOCK Study Horizon 1.5 Duke IRB Pro00011196 with a current or prior diagnosis of severe acne AND current or prior treatment with oral isotretinoin. All 250 participants will answer a 5-page questionnaire designed to collect information on the diagnosis of severe acne and response to oral isotretinoin treatment. The aim is to identify genetic predictors of severe acne vulgaris and the outcome of oral isotretinoin treatment. 