A 5 year old child develops non blanching macules, papules and petecheal hemorrhage on lower extremities, mild abdominal pain, and skin biopsy showed IgA deposition along blood vessels and perivascular neutrophilic infiltrate. Most probably diagnosis is
**Core Concept**
The question describes a clinical scenario of a 5-year-old child presenting with non-blanching macules, papules, and petechial hemorrhage on the lower extremities, along with mild abdominal pain. The skin biopsy findings of IgA deposition along blood vessels and perivascular neutrophilic infiltrate are key diagnostic clues.
**Why the Correct Answer is Right**
The clinical presentation and biopsy findings are consistent with Henoch-Schönlein purpura (HSP), a form of vasculitis that primarily affects children. The deposition of IgA antibodies along the blood vessels is a hallmark of HSP, leading to the activation of complement and subsequent inflammation. The perivascular neutrophilic infiltrate further supports this diagnosis, indicating an immune-mediated response. The abdominal pain is also a common symptom of HSP, due to the involvement of the gastrointestinal tract.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is likely a distractor, as it does not match the clinical presentation or biopsy findings described in the question.
**Option B:** This option may be a consideration in some cases of vasculitis, but the specific findings of IgA deposition and perivascular neutrophilic infiltrate point towards HSP rather than another diagnosis.
**Option C:** This option is not relevant to the clinical scenario described, as it does not involve a vasculitic process or the specific biopsy findings mentioned.
**Option D:** This option may be a consideration in some cases of vasculitis, but the clinical presentation and biopsy findings are more consistent with HSP than another diagnosis.
**Clinical Pearl / High-Yield Fact**
Henoch-Schönlein purpura is a form of vasculitis that primarily affects children, and the diagnosis can be supported by the presence of non-thrombocytopenic purpura, abdominal pain, and IgA deposition along blood vessels on skin biopsy.
**Correct Answer:** C.