A child develops non-blanching macules and papules on lower extremities, mild abdominal pain and skin biopsy showed IgA deposition. Most appropriate diagnosis is –
**Core Concept**
The question is testing the student's knowledge of Henoch-Schönlein purpura (HSP), a form of vasculitis characterized by IgA deposition and affecting small blood vessels, leading to skin, gastrointestinal, and renal manifestations.
**Why the Correct Answer is Right**
HSP is a classic example of a small-vessel vasculitis, often caused by IgA deposition in the affected tissues. The presence of non-blanching macules and papules on the lower extremities, along with mild abdominal pain, is consistent with HSP. The skin biopsy showing IgA deposition is a key diagnostic finding, confirming the presence of this autoimmune disorder. IgA deposition can lead to inflammation and damage to the blood vessels, resulting in the characteristic symptoms of HSP.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is likely a distractor, as it does not describe a condition associated with IgA deposition and small-vessel vasculitis.
**Option B:** This option is incorrect, as it does not match the clinical presentation of HSP.
**Option C:** This option is a distractor, as it does not accurately describe the condition characterized by IgA deposition and small-vessel vasculitis.
**Clinical Pearl / High-Yield Fact**
Remember that Henoch-Schönlein purpura is a classic example of a small-vessel vasculitis, and the presence of IgA deposition in skin biopsy is a key diagnostic finding. This condition can affect multiple systems, including skin, gastrointestinal, and renal systems.
**Correct Answer:** C.