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

  • Alternative Names
    • Blood spots; Skin hemorrhages

  • 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
  • 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:

      • Is this the first time you have had such spots?
      • When did they develop?
      • What color are they?
      • Do they look like bruises?
      • What medicines 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. Blood tests may be ordered to determine the cause of the purpura.

  • References
    • Marks JG, Miller JJ. Purpura. In: Marks JG, Miller JJ, eds. Lookingbill and Marks' Principles of Dermatology. 5th ed. Philadelphia, PA: Elsevier Saunders; 2013:chap 17.