You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is A child develops non-blanching Macules and papules on lower extremities, mild abdominal pain and skin biopsy showed IgA deposition. Most appropriate diagnosis is – and explain in detail?
H.S. purpura is characterized by a tetrad of
Purpura,
Arthritis,
Glomerulonephritis and
Abdominal pain.

Diagnosis of H.S.purpura

Diagnosis is based on signs and symptoms.
Skin biopsy demonstrates leukocytoclastic vasculitis with IgA and C3 deposition.
Renal biopsy demonstrates IgA in mesangium.