Palpable Purpura in a Boy With Abdominal Pain: Challenge
On hospitalization day 2, the patient developed painful palpable purpura of the left cheek as well as scattered purpura and petechiae of bilateral arms. These lesions quickly progressed to symmetrically involve the buttocks, thighs, and ankles, bilaterally (Fig. 1). After this, he had 3 episodes of bloody stool incontinence. Soft-tissue lumbar swelling was also noted. Over subsequent days, he developed joint pain of wrists, low back, knees, and ankles aggravated by ambulation. Oral intake became painful at which point soft palate petechiae were noted.