WBR0872
| Author | [[PageAuthor::Rim Halaby, M.D. [1]]] |
|---|---|
| Exam Type | ExamType::USMLE Step 1 |
| Main Category | MainCategory::Pathology |
| Sub Category | SubCategory::Musculoskeletal/Rheumatology |
| Prompt | [[Prompt::A 19 year old girl presents to the emergency department for 2 days of severe abdominal pain involving mainly the upper quadrants. Although the pain had started insidiously, it had become unbearable. She also decided to seek medical care because she started noticing blood in her stools. The patient denies consuming any food other than her home cooking. Upon further questioning, the patient reports recent onset articular pain she attributed to recent heavy exercise. On exam, the attending physician notes several findings including cervical lymphadenopathy, a nontender palpable purpuric rash in the lower extremities, and moderate nonpitting pedal edema. If the physician was to biopsy the patient's rash, which of the following findings would be expected on immunofluorescence?]] |
| Answer A | AnswerA::IgG, C3 and C4 deposits |
| Answer A Explanation | AnswerAExp:: |
| Answer B | AnswerB::IgG, IgM, and C3 deposits |
| Answer B Explanation | AnswerBExp:: |
| Answer C | AnswerC::IgE deposits |
| Answer C Explanation | AnswerCExp:: |
| Answer D | AnswerD::IgA and C3 deposits |
| Answer D Explanation | AnswerDExp:: |
| Answer E | AnswerE::IgA deposits |
| Answer E Explanation | AnswerEExp:: |
| Right Answer | RightAnswer::D |
| Explanation | [[Explanation::Henoch-Schönlein purpura (HSP) is a systemic disease characterized by vasculitis of the small vessels caused by immune deposits of IgA and C3 in arterioles, venules, and capillaries. Clinically the classic triad of HSP includes a skin rash mostly seen on the lower extremities and classically described as palpable purpura, arthralgias, and abdominal pain sometimes associated with vomiting, diarrhea, melena, or hematochezia. HSP is generally a pediatric disease although it can occur much less commonly in adults. HSP is closely related to IgA nephropathy as both diseases share a similar pathogenesis, with renal insufficiency being an important complication of HSP. In general, most cases are self-limited and only require supportive therapy. The abdominal pain usually subsides within a few days and most patients do not have recurrences.
Educationa objective: Henoch-Schönlein purpura (HSP) is a systemic disease characterized by vasculitis of the small vessels caused by immune deposits of IgA and C3 often presenting with a triad of palpable purpura, abdominal pain, and arthralgia.
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| Approved | Approved::No |
| Keyword | WBRKeyword::Henoch-Schonlein Purpura, WBRKeyword::HSP, WBRKeyword::IgA, WBRKeyword::C3 |
| Linked Question | Linked:: |
| Order in Linked Questions | LinkedOrder:: |