Purpura

: A hemorrhage area in the surface of the skin. The affected area of skin with purpura is greater than 3 millimeters in diameter. The appearance of an individual area of purpura varies with the duration of the lesions. Early purpura is red and becomes darker, then purple, and brown-yellow as it fades. Purpura does not blanch when touched.

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A condition characterized by hemorrhage into the skin. Appearance of the lesions varies with the type of p., the duration of the lesions, and the acuteness of the onset. The color is first red, gradually darkens to purple, fades to a brownish yellow, and usually disappears in 2 or 3 weeks; color of residual permanent pigmentation depends largely on the type of unabsorbed pigment of the extravasated blood; extravasations may occur also into the mucous membranes and internal organs. SYN: peliosis. [L. fr. G. porphyra, purple]

- allergic p. nonthrombocytopenic p. due to sensitization to foods, drugs, and insect bites. SYN: anaphylactoid p. (1).

- anaphylactoid p. 1. SYN: allergic p.. 2. SYN: Henoch-Schönlein p..

- p. angioneurotica an eruption marked by angioneurotic edema, petechiae, and hyperesthesia of the skin and gastric mucous membrane.

- p. annularis telangiectodes asymptomatic annular lesions, principally of the lower extremities of adolescent males, in which the peripheral portion is composed of p. or petechiae with brawny staining of hemosiderin deposits and minute telangiectasia.

- factitious p. self-induced, often painful, ecchymoses.

- fibrinolytic p. p. in which the bleeding is associated with rapid fibrinolysis of the clot.

- p. fulminans a severe and rapidly fatal form of p. hemorrhagica, occurring especially in children, with hypotension, fever, and disseminated intravascular coagulation, usually following an infectious illness.

- Henoch p. SYN: Henoch-Schönlein p..

- Henoch-Schönlein p. an eruption of nonthrombocytopenic, palpable purpuric lesions due to dermal leukocytoclastic vasculitis with IgA in vessel walls associated with joint pain and swelling, colic, and passage of bloody stools, and occurring characteristically in young children; glomerulonephritis may occur during an initial episode or develop later. SYN: anaphylactoid p. (2), Henoch p., Henoch-Schönlein syndrome, p. rheumatica, Schönlein p., Schönlein-Henoch syndrome.

- hyperglobulinemic p. SYN: Waldenström macroglobulinemia.

- idiopathic thrombocytopenic p. (ITP) a systemic illness characterized by extensive ecchymoses and hemorrhages from mucous membranes and very low platelet counts; resulting from platelet destruction by macrophages due to an antiplatelet factor; childhood cases are usually brief and rarely present with intracranial hemorrhages, but adult cases are often recurrent and have a higher incidence of grave bleeding, especially intracranial. SYN: immune thrombocytopenic p., thrombopenic p..

- immune thrombocytopenic p. SYN: idiopathic thrombocytopenic p..

- nonthrombocytopenic p. SYN: p. simplex.

- psychogenic p. a psychosomatic condition similar to autoerythrocyte sensitization syndrome.

- p. pulicans, p. pulicosa petechiae caused by the bites of insects and animal parasites.

- p. rheumatica SYN: Henoch-Schönlein p..

- Schönlein p. SYN: Henoch-Schönlein p..

- p. senilis the occurrence of petechiae and ecchymoses on the atrophic skin of the legs in aged and debilitated subjects.

- p. simplex the eruption of petechiae or larger ecchymoses, usually unaccompanied by constitutional symptoms and not associated with systemic illness. SYN: nonthrombocytopenic p..

- p. symptomatica a petechial eruption in scarlet fever and other exanthemas.

- thrombocytopenic p. idiopathic thrombocytopenic p..

- thrombopenic p. SYN: idiopathic thrombocytopenic p..

- thrombotic thrombocytopenic p. a rapidly fatal or occasionally protracted disease with varied symptoms in addition to p., including signs of central nervous system involvement, due to formation of fibrin or platelet thrombi in arterioles and capillaries in many organs.

- p. urticans p. simplex accompanied by an urticarial eruption.

- Waldenström p. SYN: Waldenström macroglobulinemia.

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pur·pu·ra 'pər-p(y)ə-rə n any of several hemorrhagic states characterized by patches of purplish discoloration resulting from extravasation of blood into the skin and mucous membranes see THROMBOCYTOPENIC PURPURA

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n.

a skin rash resulting from bleeding into the skin from small blood vessels (capillaries); the individual purple spots of the rash are called petechiae. Purpura may be due either to defects in the capillaries (nonthrombocytopenic purpura) or to a deficiency of blood platelets (thrombocytopenic purpura). See Henoch-Schönlein purpura, idiopathic thrombocytopenic purpura, thrombocytopenia.

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Pur·pu·ra (purґpu-rə) a genus of marine snails of the family Muricidae. Some species furnish a purple dye and others contain the neurotoxin purpurine or murine.