Case Summary

A 20-year-old man presented to the emergency department with history of recent upper respiratory infection treated with penicillin and a 3-day history of abdominal pain. Physical examination revealed right lower quadrant tenderness but was otherwise unremarkable. Laboratory evaluation revealed leukocytosis, and an enhanced computed tomography (CT) scan of the abdomen and pelvis was obtained (Figure 1). The patient was admitted for 24-hour observation and improved markedly with intravenous (IV) fluids. Stool culture and all other laboratory studies were negative. Three days after dismissal, the patient developed a nonpruritic eruption involving the lower extremities. Skin examination revealed scattered deep red to purple papules, ranging in size from 2 to 5 mm, extending from his feet to proximal thighs bilaterally (Figure 2).

Figure 2

Diagnosis

Henoch-Schönlein purpura

Imaging Findings

CT of the abdomen and pelvis with oral and IV contrast revealed thickening of the distal ileum and mesenteric vascular engorgement (Figure 1). Imaging findings were nonspecific, and diagnostic considerations included inflammatory bowel disease, such as Crohn's and infectious enteritis. Neoplastic conditions, such as lymphoma, were a much less likely consideration. The patient had no history of a bleeding disorder, such as leukemia or hemophilia.

Pathologic Findings

Skin biopsy of one papule demonstrated leukocytoclastic vasculitis on routine histology (Figure 3) and vascular deposition of IgA by direct immunofluorescence (not shown), confirming the diagnosis of Henoch-Schönlein purpura. In the gastrointestinal system, the pathologic findings are of submucosal and mural infiltration of the bowel wall by blood or edema, causing an intense scarlet color.¹ Microscopically, endothelial proliferation and thrombosis of small arterioles consistent with vasculitis are seen.¹

The patient was treated with steroids, and the symptoms and skin lesions resolved completely.

Figure 1

Discussion

Henoch-Schönlein syndrome is a systemic vasculitis affecting small vessels. The cause is unknown, but immunizations, insect bites, medications, infections, and certain foods may have a role in the etiology of this entity.² Though it commonly affects children, it can also affect adult patients. The diagnosis is based on characteristic clinical signs and symptoms, such as skin rash, arthritis involvement of the large joints, abdominal pain, gastrointestinal bleeding, and hematuria. Systemic manifestations occur in 80% of patients.² The skin is typically involved first, and the rash has a predilection for the buttocks and lower extremities.² Gastrointestinal involvement occurs in more than half of patients² and is thought to be related to edema and intramural hemor-rhage. The CT imaging findings have been previously described^3-5 and consist of bowel wall thickening, mesenteric vessels engorgement, mesenteric lympha-denopathy, mesenteric fat edema, and other less common findings, such as ascites, pleural effusion, and renal or splenic infarct. The disease distribution on a series of 22 patients was as follows: 11 in the duodenum and jejunum or jejunum alone, 3 proximal jejunum to distal ileum, 3 isolated terminal ileum, 2 colon, and 3 patients had small bowel intussusception.¹ Complications may occur and result in perforation, intussusception, and obstruction.¹ Henoch-Schönlein purpura usually remits spontaneously, although symptomatic improvement is obtained with steroids.⁶

Conclusion

Henoch-Schönlein syndrome should be included in the differential diagnosis of young patients with nonspecific CT findings of bowel wall thickening and mesenteric vessels engorgement with or without adenopathy. The radiologist should be aware of the imaging findings, since the diagnosis can be challenging in the absence of the typical clinical findings such as skin rash, hematuria, arthralgia, abdominal pain, nausea, vomiting, and melena.

References

1. Glasier CM, Siegel MJ, McAlister WH, Shackelford GD. Henoch-Schönlein syndrome in children: Gastrointestinal manifestations. AJR Am J Roentgenol. 1981;136:1081-1085.
2. Schaller JG. Rheumatic diseases of childhood (inflammatory diseases of connective tissue, collagen diseases). In: Behrman RE, ed. Nelson Textbook of Pediatrics. 14th ed. Philadelphia, PA: Saunders; 1992:628-629.
3. Demirci A, Cengiz K, Baris S, Karagoz F. CT and ultrasound of abdominal hemorrhage in Henoch-Schönlein purpura. J Comput Assist Tomogr. 1991;15:143-145.
4. Jeong YK, Ha HK, Yoon CH, et al. Gastrointestinal involvement in Henoch-Schönlein syndrome: CT findings. AJR Am J Roentgenol. 1997;168:965-968.
5. Siskind BN, Burrell MI, Pun H, et al. CT demonstration of gastrointestinal involvement in Henoch-Schönlein syndrome. Gastrointest Radiol. 1985;10:352-354.
6. Schuman M. Hemorrhagic disorders: Abnormalities of platelet and vascular function. In: Goldman L, Bennett JC, eds. Cecil Textbook of Medicine. 21st ed. Philadelphia, PA: Saunders; 2000:1004.

Figure 3