system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A 5 year old child presents with perivascular IgA deposition and neutrophilic collection. There is erythematous rash on the lower limb and nonblanching purpura. Probable diagnosis is
assistant
The correct answer is  Henoch schonlein purpura : It is one of the most common vasculitic disorder of childhood. Characterised by the presence of nonthrombocytopenic , palpable purpura, transient ahralgia and abdominal symptoms. The illness begins with a rash more prominent over the extensor aspects of lower extremities and buttocks. It may be macular, maculopapular or even uicarial to begin with . Glomerulonephritis seen in one third of cases. Gastrointestinal manifestations usually occur in first 7-10 days if illness. Abdominal pain is intermittent, colicky and periumbilical.vomitingseen , whereas melena and hemetemesis are less common. Rare manifestations include CNS vasculitis, coma, Guillain Barre syndrome, pulmonary hemorrhage, carditis and orchitis. Criteria for childhood HSP:- Palpable purpura in the presence of at least one of the following 4 features: 1. Diffuse abdominal pain. 2. Any deposit showing IgA deposition. 3. Ahritis/Ahralgia. 4. Renal involvement. Investigation: Nonspecific rise in total serum IgA levels. Skin biopsy shows leukocytoclastic vasculitis. On indirect immunofluorescence there are mesangial deposits of IgA andC3 in skin and renal biopsy. Reference: GHAI essential Paediatrics