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: Skin
[{'content': 'Palpable purpura are seen in all EXCEPT: \nSelect and explain. \nA. Giant cell aeritis, B. HSP, C. Wegner granulomatosis, D. Polyaeritis nodosa', 'role': 'user'}, {'content': 'Answer: A \nExplanation: Giant cell aeritis REF: Harrison\'s 18\' ed chapter 53 table 54-16 "Giant cell aeritis being a large vessel vasculitis does not cause any purpura" CAUSES OF PURPURA: Palpable Non palpable Primary cutaneous Trauma disorder Solar purpura Steroid purpura Capillaritis Livedoid vasculopathy Systemic disorder Vasculitis Vascular fragility * Cutaneous small-vessel * Amyloidosis vasculitis (Henoch-Schanlein * Ehlers-Danlos syndrome purpura, Acute hemorrhagic * Scurvy edema of infancy, Uicarial Thrombi vasculitis, Cryoglobulinemic * DIC vasculitis, Erythema elevatum * Monoclonal cryoglobulinemia diutinum, Granuloma faciale) * TTP * Polyaeritis nodosa * Warfarin reaction Emboli Emboli * Acute meningococcemia * Cholesterol * Disseminated gonococcal * Fat infection Possible immune complex * Rocky Mountain spotted fever * Gardner-Diamond syndrome * Ecthyma gangrenosum (autoerythrocyte sensitivity) * Waldenstrom\'s hypergammaglobulinemic purpura Clotting disturbances * ITP * Abnormal platelet function * Clotting factor defects', 'role': 'assistant'}]