A 10 year old male child presents with purpuric rashes on the lower extremities, hematuria, abdominal pain, and ahritis but has no history of fever. What is the likely diagnosis ?
**Core Concept**
The child's presentation suggests a systemic vasculitis involving small-sized blood vessels, which is a hallmark of Henoch-Schönlein purpura (HSP). HSP is a form of IgA-mediated vasculitis that primarily affects children.
**Why the Correct Answer is Right**
Henoch-Schönlein purpura is characterized by the deposition of IgA immune complexes in the walls of small blood vessels, leading to inflammation and damage. This results in the typical symptoms of purpuric rash, abdominal pain, arthritis, and glomerulonephritis (manifesting as hematuria). The absence of fever is a distinguishing feature of HSP from other forms of vasculitis. The kidneys are commonly involved in HSP, and the presence of hematuria indicates renal involvement.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is unlikely as Henoch-Schönlein purpura is a distinct clinical entity and not a manifestation of Kawasaki disease, which presents with fever, conjunctivitis, and lymphadenopathy.
**Option B:** This option is incorrect as Goodpasture syndrome primarily involves the lungs and kidneys, presenting with hemoptysis and renal failure, which is not consistent with the child's symptoms.
**Option C:** This option is incorrect as polyarteritis nodosa (PAN) is a medium-sized vessel vasculitis that typically presents with hypertension, abdominal pain, and renal failure, which is not consistent with the child's symptoms.
**Option D:** This option is incorrect as systemic lupus erythematosus (SLE) is a multisystem autoimmune disease that can present with a wide range of symptoms, including vasculitis, but the absence of fever and specific autoantibodies makes this diagnosis less likely.
**Clinical Pearl / High-Yield Fact**
Henoch-Schönlein purpura is a classic example of an IgA-mediated vasculitis, which highlights the importance of considering immune complex deposition in the pathogenesis of various vasculitic syndromes.
**Correct Answer:** C.