A 16-year-old boy with autism presented with 4 weeks of progressive bilateral lower extremity edema, ecchymosis, and arthralgias severe enough to prevent ambulation. Associated symptoms included fatigue, decreased appetite, abdominal discomfort, and intermittent scleral icterus noted by his mother. One week prior, a dentist diagnosed acute necrotizing gingivostomatitis based on gum inflammation and bleeding, prompting treatment with metronidazole and penicillin. There was no history of trauma, fevers, hematuria, or hematochezia or family history of coagulation disorders. His medical history was significant for seizures and behavioral disturbances managed with stable doses of lamotrigine and chlorpromazine. On physical examination, he was nonverbal but in no visible distress. There was hemorrhagic gingivitis (Figure, A) without cervical lymphadenopathy, and the bilateral lower extremities had marked asymmetric pitting edema, large ecchymoses on the thighs, ankles, and feet (Figure, B), and scattered petechiae (Figure, C). His lower extremities were tender to palpation and he resisted passive ranging of his joints.
Jacobsen A, DeNiro K. Rash and Arthralgias in a Teenager With Autism. JAMA Pediatr. 2017;171(1):89-90. doi:10.1001/jamapediatrics.2016.1565