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

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.

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

Call your doctor for an appointment if you have signs of purpura.

Your doctor will examine your skin and ask you questions about your medical history and symptoms, including:

• Is this the first time you have had such spots?
• When did they develop?
• What color are they?
• Do they look like bruises?
• What medications do you take?
• What other medical problems have you had?
• Does anyone in your family have similar spots?
• What other symptoms do you have?

A skin biopsy may be done.

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.