purpura fulminans symptomstreatment for purpura and petechiaeidiopathic thrombotic purpurathrombo thrombocytopenic purpuraallergic purpura symptomspurpura itchingsenile purpura symptomshenoch purpura symptomspurpura rash treatmentpurpura fulminans symptomespetechiae skin purpurahenoch schonlein purpura symptoms