Purpura is purple-colored spots and patches that occur on the skin, and in mucus membranes, including the lining of the mouth.
Purpura occurs when small blood vessels leak blood under the skin.
When purpura spots are less than 3 millimeters in diameter, they are called petechiae. Purpura spots larger than 1 centimeter 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).
Causes of Purpura
Nonthrombocytopenic purpuras may be due to:
- Blood clotting disorders
- Congenital cytomegalovirus
- Congenital rubella syndrome
- Drugs that affect platelet function
- Fragile blood vessels seen in older people (senile purpura)
- 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
- Steroid use
Thrombocytopenic purpura may be due to:
- Drugs that reduce the platelet count
- Idiopathic thrombocytopenic purpura (ITP)
- Immune neonatal thrombocytopenia (can occur in infants whose mothers have ITP)
- Meningococcemia -- a raised type of purpura
When to Contact a Health Professional
Call your doctor for an appointment if you have signs of purpura.
What to Expect at Your Office Visit
Your doctor will examine your skin and ask 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.
Korman NJ. Macular, papular, vesiculobullous, and pustular diseases. In: Goldman L, Schafer AI, eds. Goldman's Cecil Medicine. 24th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 447.
|Review Date: 4/24/2013
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, Bethanne Black, Stephanie Slon, and Nissi Wang.
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