Lip abscess associated with isotretinoin treatment of acne vulgaris.

IMPORTANCE: Isotretinoin is frequently prescribed for the treatment of acne vulgaris. Among the numerous documented adverse effects, most common are xerostomia and cheilitis. Lip abscesses as a consequence of cheilitis present dramatically and may pose a diagnostic challenge. OBSERVATIONS: We present a case of a 15-year-old boy with a severe lip abscess requiring incision and drainage and hospital admission for intravenous antibiotic treatment of methicillin-resistant Staphylococcus aureus. We discuss the pathophysiologic characteristics of isotretinoin therapy and the likely causative role that the medication played in the development of the lip abscess. CONCLUSIONS AND RELEVANCE: Although rare, lip abscesses related to isotretinoin therapy present with substantial morbidity and should be promptly recognized. Misdiagnosis of mucositis and angioedema may delay appropriate therapy.