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.