Bruising

Basics

Description

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

Epidemiology

Prevalence

  • <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.

Genetics

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

Pathophysiology

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

Etiology

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

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