Purpura

Definition:

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

Alternative Names:

Blood spots; Skin hemorrhages

Considerations:

Purpura occurs when small blood vessels join together or leak blood under the skin.

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

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

Common Causes:

Nonthrombocytopenic purpuras may be due to:

Amyloidosis
Blood clotting disorders
Congenital cytomegalovirus
Congenital rubella syndrome
Drugs that affect platelet function
Fragile blood vessels (senile purpura)
Hemangioma
Inflammation of the blood vessels (vasculitis), such as Henoch-Schonlein purpura, which causes a raised type of purpura
Pressure changes that occur during vaginal childbirth
Scurvy
Steroid use

Thrombocytopenic purpura may be due to:

Drugs that prevent platelets from forming
Idiopathic thrombocytopenic purpura (ITP)
Immune neonatal thrombocytopenia (can occur in infants whose mothers have ITP)
Meningococcemia -- a raised type of purpura

Call your health care provider if:

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

What to expect at your health care provider's office:

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.

References:

Korman NJ. Macular, papular, vesicobullous, and pustular diseases. In: Goldman L, Ausiello D. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 465.

Coller BS, Schneidermann PI. Clinical evaluation of hemorrhagic disorders: the bleeding history and differential diagnosis of purpura. In: Hoffman R, Benz EJ, Shattil SS, et al. Hematology: Basic Principles and Practice. 5th ed. Philadelphia, Pa: Churchill Livingstone; 2008: chap 121.