Case presentation: An 18-year-old male with no previous medical history presented with rash, abdominal pain. The rash began on his thighs and spread to all four extremities. He also reported 1 week history of watery diarrhea and nausea. He was unable to tolerate oral intake and sustained a 12 pound weight loss. He denied fevers, chills, arthralgias, oral ulcers, hematuria, hematochezia, melena, or preceding viral symptoms. He denied non-steroidal anti-inflammatory and alcohol use. On admission, vitals were within normal limits. Physical examination was significant for a non-raised petechial rash over the upper and lower extremities, which involved the feet and palms of his hands (Figure 1). Oropharynx, abdominal, and joint exam did not reveal any abnormalities.Figure 1Upper endoscopy reported moderate to severe active gastritis with ulcerations and mild duodenitis with ulcerations (Figure 2). Gastric and duodenal biopsies were negative for Helicobacter pylori, cytomegalovirus, herpes simplex virus, and adenovirus. A punch biopsy of the skin was performed and showed leukocytoclastic vasculitis with IgA deposits on immunochemical staining suggestive of HSP. Laboratory studies were unremarkable except for evidence of mild leukocytosis.Figure 2The patient was treated with supportive care including proton pump inhibitor therapy. His symptoms improved within several days of hospitalization. Discussion: HSP is a systemic small vessel vasculitis characterized by IgA immune complex deposition in capillaries of the skin, gastrointestinal tract, joints and kidneys. This condition is often self-limited and more commonly observed in children compared to adults. The classic presentation includes abdominal pain, palpable purpura, renal dysfunction and/or arthalgias. Abdominal pain can be secondary to several etiologies with varying clinical presentations. IgA deposition in capillaries of the gastrointestinal tract can cause small vessel thrombosis, leading to mucosal hemorrhage, bowel ischemia and ulcerations. Gastric hemorrhage often leads to epigastric pain. Bleeding into the submucosal space can lead to small bowel hematomas and intussusceptions, and patients can present with symptoms of small bowel obstruction. A high index of suspicion is needed for the diagnosis of HSP in patients that present with atypical signs and symptoms. Our patient presented with a petechial rash that is not classic for HSP but suggestive of a vasculitis. The symptoms of acute onset of abdominal pain in an otherwise healthy young adult suggested the diagnosis. Endoscopy and skin biopsy are often necessary to confirm the diagnosis. Cross-sectional imaging may be warranted if upper endoscopy is unremarkable.