Background YouTube is one of the most popular video-sharing websites in Korea, but incorrect or biased information is not properly regulated. Acne is common in adolescents and young adults who are familiar with YouTube. Thus, misleading information about isotretinoin in YouTube videos could distort the perception of treatment. Objective We evaluated the quality of information about isotretinoin in YouTube videos. Methods The keywords searched on YouTube Korea on July 1, 2020 were: isotretinoin, Roaccutane, and Isotinone. The DISCERN tool was used to evaluate the reliability and quality of information, and eight items were used to evaluate scientific accuracy and comprehensiveness: mechanism, indications, dose regimen, contraindications, side effects, blood tests, drug interactions, and pregnancy-related issues. Results The number of videos searched was 728. After excluding duplicate or inappropriate videos, 164 videos were analyzed. In the DISCERN tool, the mean overall quality score was 2.24 on a 5-point scale from 1 to 5. The mean score in the 8-issue-criteria, a 3-point scale from 0 to 2, was 0.61. Particularly, indications, blood tests, and drug interactions were poorly addressed in YouTube videos. Medical personnel offer better video quality than non-medical personnel. However, no significant difference in quality existed between the videos of dermatologists and those of other medical personnel. The quality score was not correlated with the popularity of the video. Conclusion YouTube videos covering isotretinoin showed poor overall quality. Content quality did not have a significant correlation with popularity, so incorrect information could be propagated on YouTube.

A woman in her 40s presented with painful erythematous plaques on her trunk (Figure , A). Skin lesions developed 2 months earlier and progressively spread. She reported abdominal discomfort, weight loss, and vaginal bleeding. A solid mass on her lower abdomen that had been palpable about 10 years prior had rapidly increased in size within the past few months. Physical examination revealed erythematous plaques on the right chest and flank without warmth. Punch biopsy of a lesion from the chest was sent for histopathological examination (Figure, B and C).