A rash in the setting of colicky abdominal pain and polyarthralgia suggest Henoch-Schonlein Purpura (HSP). The course of the disease is usually self-limited but glomerulonephritis and potentially ESRD are long-term complications in some patients.
HSP is a small vessel, leukocytoclastic angiitis associated with IgA and C3 deposition. It presents in children (ages 3-11) with colicky abdominal pain, a typical dependent purpuric rash on the lower extremities, and polyarthralgia, often in the large joints of the lower extremities. It is often related to recent infection. Diagnosis is based on clinical criteria from the American College of Rheumatology. If uncertainty exists, a skin biopsy demonstrating leukocystoclastic vasculitis with IgA deposits is conclusive. Treatment is supportive as the disease is usually self-limited though controversy about use of steroids exists.
Reamy et al. review HSP and discuss the fact that although 90% of cases of HSP are identified in children <10 years old, adults may be more likely to develop subsequent renal complications. They report that all patients with HSP have rash, 75% have arthritis, 60-65% have abdominal pain, and 40-50% develop renal disease.
Dudley et al. found in a randomized, controlled trial with high dropout rate that treatment with two weeks of prednisolone did not alter the incidence of proteinurea at one year among children with HSP. 352 children randomized, and at one year, 18/123 (15%) patients on prednisolone and 13/124 (10%) patients on placebo had proteinurea. They argue that this is evidence against the use of steroids in HSP.
Image A shows the dependent purpuric rash covering the lower extremities that is characteristic of HSP.
Answer 1: Septic shock may rapidly result from meningococcemia, a possible cause of purpura in young children that is less likely given the distribution of this patient's rash and concordant abdominal pain.
Answer 3: Congenital rubella may cause a purpuric, "blueberry-muffin" rash in neonates and may also cause deafness.
Answer 4: Rheumatic fever results from untreated Group A streptococcal infection. GAS infections may cause cellulitis, erysipelas or impetigo, but do not typically cause a purpuric rash like the one seen in Image A.
Answer 5: Bowel ischemia and necrosis requiring surgical resection are typical of intussusception, although that is less likely here given the rash.
Reamy BV, Williams PM, Lindsay TJ. Henoch-Schönlein purpura. Am Fam Physician. 2009 Oct 1;80(7):697-704. PubMed PMID: 19817340
PMID:19817340 (Link to Abstract)
Dudley J, Smith G, Llewelyn-Edwards A, Bayliss K, Pike K, Tizard J. Randomised, double-blind, placebo-controlled trial to determine whether steroids reduce the incidence and severity of nephropathy in Henoch-Schonlein Purpura (HSP). Arch Dis Child. 2013 Oct;98(10):756-763. doi: 10.1136/archdischild-2013-303642. Epub 2013 Jul 11. PubMed PMID: 23845696
PMID:23845696 (Link to Abstract)
USMLE World Step 1 QBank Question #458. Copyright © USMLEWorld, LLC 2012