This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Medicine
Henoch Schonlein purpura presents with deposition of: 
Select and explain. 
A. IgG, B. IgA, C. IgM, D. IgE
B: IgA
Answer: B: IgA 
Explanation: Henoch-Schonlein purpura, the most common systemic vasculitis in children. Typical features are palpable purpura, abdominal pain, ahritis, and hematuria. Direct immunofluorescence of the skin lesions demonstrates immunoglobulin deposition in and about affected blood vessels. All immunoglobulin classes may be present, but IgA is always present. Many times, it is the only immunoglobulin detected. Ref: Cutaneous Medicine: Cutaneous Manifestations of Systemic Disease By John A. Flynn (MD.), Thomas T. Provost, John A Flynn, 2001, Page 180 ; Harrison's 17th ed chapter 319