vascular purpura

purpura

a hemorrhagic disease characterized by extravasation of blood into the tissues, under the skin and through the mucous membranes, and producing spontaneous ecchymoses and petechiae on the skin. Similar lesions are produced in many specific diseases, e.g. epizootic hemorrhagic disease of deer, bracken poisoning in cattle, and leptospirosis in calves. In immune-mediated purpura there is a defect in the integrity of the vessel wall due to immunological mechanisms, which may also cause a thrombocytopenia.

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anaphylactoid purpura

immune-mediated purpura; see also purpura.

fibrinolytic purpura

purpura associated with increased fibrinolytic activity of the blood.

purpura hemorrhagica

a well-defined disease of horses, occurring sporadically, usually associated with a respiratory tract infection. Clinical signs include cold, subcutaneous, edematous swellings, usually about the head and not always symmetrical, mucosal petechiation and high heart rate; affected horses commonly die within a few days. Nonthrombocytopenic.

neonatal purpura

alloimmune hemolytic anemia of the newborn in pigs is sometimes accompanied by a thrombocytopenic purpura, caused by antiplatelet antibodies. See also alloimmune thrombocytopenia.

nonthrombocytopenic purpura

purpura without any decrease in the platelet count of the blood. In such cases the cause of purpura is either abnormal capillary fragility or a clotting factor deficiency.

thrombocytopenic purpura

purpura associated with a decrease in the number of platelets in the blood. See also immune-mediated thrombocytopenia.

vascular purpura

that caused by loss of vascular integrity or function, as seen in vitamin C deficiency (scurvy), diabetes mellitus and hyperadrenocorticism.

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vascular purpura

Henoch-Schönlein purpura, see there