Can urticaria cause allergic purpura

Urticaria does not cause allergic purpura. Urticaria and allergic purpura are two different and completely independent diseases that do not change from each other. Urticaria is characterized by skin itching first, then will show wheals, bright red or pale, skin color, a few cases can only edema erythema, wheals of different sizes and shapes, attack time is also uncertain, wheals generally last 24 hours will naturally subside, but can occur repeatedly, in the evening attack is more common, some patients can be accompanied by nausea, vomiting, headache, abdominal pain, diarrhea, chest tightness, heart rate acceleration, anaphylactic shock and asphyxia. Allergic purpura is a systemic small vasculitis, clinically more children and adolescents, can be divided into simple type, joint type, gastrointestinal type and renal purpura, the most common simple purpura, good occurred in the legs and limbs extension side, mainly palpable petechiae and ecchymosis.