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Purpura

• Overview

Definition:

Purpura is purple-colored spots and patches that occur on the skin, on organs, and in mucous membranes, including the lining of the mouth.

Alternative Names:

Blood spots; Skin hemorrhages

Considerations:

Purpura occurs when small blood vessels under the skin leak.

When purpura spots are very small, they are called petechiae . Large purpura are called ecchymoses.

A person with purpura may have normal platelet counts (nonthrombocytopenic purpuras) or decreased platelet counts (thrombocytopenic purpuras). Platelets help the blood clot.

Common Causes:

Nonthrombocytopenic purpuras may be due to:

• Drugs that affect platelet function
• Congenital cytomegalovirus
• Congenital rubella syndrome
• Fragile blood vessels (senile purpura)
• Pressure changes that occur during vaginal childbirth
• Vasculitis such as Henoch-Schonlein purpura

Thrombocytopenic purpura may be due to:

• Drugs that prevent platelets from forming
• Hemangioma
• Idiopathic thrombocytopenic purpura (ITP)
• Immune neonatal thrombocytopenia (can occur in infants whose mothers have ITP)
• Meningococcemia

References:

Goldman L, Ausiello D. Cecil Textbook of Medicine . 22nd ed. Philadelphia, Pa: WB Saunders; 2004:2410.

Hoffman R, Benz EJ, Shattil SS, et al. Hematology: Basic Principles and Practice . 4th ed. Orlando, Fl: Churchill Livingstone; 2005.

• Review Date: 4/12/2007
• Reviewed By: Kevin Berman, MD, PhD, Associate, Atlanta Center for Dermatologic Disease, Atlanta, GA. Review provided by VeriMed Healthcare Network.

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