Purpura

Definition

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

Considerations

Purpura occurs when small blood vessels leak blood under the skin.

Purpura measure between 4 and 10 mm (millimeters) in diameter. When purpura spots are less than 4 mm in diameter, they are called petechiae. Purpura spots larger than 1 cm (centimeter) are called ecchymoses.

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

Causes

Non-thrombocytopenic purpuras may be due to:

Thrombocytopenic purpura may be due to:

When to Contact a Medical Professional

Call your health care provider for an appointment if you have signs of purpura.

What to Expect at Your Office Visit

The provider will examine your skin and ask about your medical history and symptoms, including:

A skin biopsy may be done. Blood and urine tests may be ordered to determine the cause of the purpura.


Review Date: 4/16/2019
Reviewed By: Michael Lehrer, MD, Clinical Associate Professor, Department of Dermatology, University of Pennsylvania Medical Center, Philadelphia, PA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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