Case Presentation: A 16-year-old Caucasian male presented to the pediatric emergency department with 10 days of worsening lumbar back pain, myalgias, difficulty ambulating and fevers. His medical history was significant for severe nodulocystic acne vulgaris, and he was started on isotretinoin at 80mg/day (1.4mg/kg/day) three weeks prior to presentation. Approximately 10 days after starting the [...]