**Question:** A four-year old child presents with mild fever, malaise, purpura, arthritis, abdominal pain and microscopic hematuria. What would be the most likely diagnosis –

A. Henoch-Schönlein Purpura (HSP)
B. Kawasaki Disease
C. Juvenile Rheumatoid Arthritis (JRA)
D. Henoch-Schönlein Purpura (HSP)

**Correct Answer:** A. Henoch-Schönlein Purpura (HSP)

**Core Concept:** Henoch-Schönlein Purpura (HSP) is a systemic vasculitis that primarily affects small blood vessels, often in children. It is characterized by palpable purpura, arthritis, abdominal pain, and microscopic hematuria.

**Why the Correct Answer is Right:** Henoch-Schönlein Purpura typically presents in children between the ages of 2 and 15 years with a female to male ratio of 2:1. The diagnosis is made based on the clinical presentation and exclusion of other causes. The key feature of HSP is the presence of purpura (non-thrush, non-traumatic petechiae), arthritis (usually oligoarticular), abdominal pain, and microscopic hematuria. The process involves an immune response leading to leukocytoclastic vasculitis, causing inflammation and damage to small blood vessels, particularly the capillaries.

**Why Each Wrong Option is Incorrect:**

B. Kawasaki Disease: Kawasaki Disease is primarily characterized by fever, mucocutaneous changes (red eyes, oral mucosa, and extremities), cervical lymphadenopathy, and cervical lymphadenopathy. HSP does not typically present with these features.

C. Juvenile Rheumatoid Arthritis (JRA): JRA is an autoimmune disorder affecting children and adults, causing chronic inflammation of joints. HSP presents with different clinical features, including purpura, abdominal pain, and microscopic hematuria, and is not a chronic joint inflammation condition.

D. Henoch-Schönlein Purpura (HSP): Despite being the correct answer, option D is repeated for clarity. HSP presents with the same clinical features as the correct answer A: purpura, arthritis, abdominal pain, and microscopic hematuria.

**Clinical Pearl:** Henoch-Schönlein Purpura is a clinical diagnosis based on the presence of the typical clinical features mentioned above. While the correct answer is D, we explain the correct answer A for clarity in comparison to other options. The clinical features of HSP are non-thrush, non-traumatic petechiae; oligoarticular arthritis; gastrointestinal symptoms, including abdominal pain; and microscopic hematuria.

**Why the Correct Answer is Right:** Henoch-Schönlein Purpura (HSP) is a small vessel vasculitis affecting children and young adults, typically presenting with a triad of clinical features: palpable purpura, arthritis, and gastrointestinal symptoms. Additionally, microscopic hematuria is often seen in HSP.

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