A 5 year old child presents with perivascular IgA deposition and neutrophilic collection. There is erythematous rash on the lower limbs and non - blanching purpura. The likely diagnosis in the child is
Henoch schonlein purpura

It is a common vasculitis in children
This is a vasculitis with IgA deposits affecting small vesseles like arterioles, capillaries and venules of the skin, gut and glomeruli and commonly associated with arthralgia.
Clinical features include palpable purpura (due to vasculitis and not reduced platelet count), colicky abdominal pain, arthalgia in multiple Joints and glomerulonephritis.
It is caused due to immune complex deposition but complement levels are usually normal.
Henoch - schonlein purpura
Wegner's granulomatosis
Gaint cell vasculitis
Kawasaki is disease