Bruises are the result of extravasation of blood into the skin. Conventional usage often groups petechiae and bruises (or ecchymoses) together as purpura and defines them as follows:

  • Petechiae: flat, red, or reddish purple; 1 to 3 mm; nonblanching
  • Ecchymoses: larger than petechiae, local extravasation, nonpulsatile, sometimes palpable, color depends on age of lesion



  • <1% nonmobile babies
  • 17% cruising and crawling infants
  • 53% walkers
  • Majority of school age children

Risk Factors

Underlying bleeding disorders (e.g., von Willebrand disease, platelet disfunction, thrombocytopenia), child abuse/trauma, medications, infections, etc. may all be risk factors leading to bruising in childhood.


  • Hemophilia is an X-linked disorder affecting males.
  • von Willebrand disease may be autosomal dominant.
  • Other platelet disorders have a variety of inheritance patterns.


Extravasation of blood from blood vessels leading to a collection of blood below the surface of the skin


  • Disorders of blood vessels and surrounding tissue
  • Platelet abnormalities (function, number)
  • Coagulation disorders

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