Bruising
BASICS
DESCRIPTION
Bruises are the result of extravasation of blood under 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
- Bruising is noted in
- <1% nonmobile babies
- 17% cruising and crawling infants
- 53% walkers
- Majority of school-age children
- Almost 20% of healthy adolescents and adults report easy bruising.
- Normal bruising is much more common than pathologic bruising.
ETIOLOGY
- Normal response to skin trauma
- Usually <1 cm and flat
- Isolated to lower extremities and forearms
- Coagulation disorders
- Platelet abnormalities (function, number)
- Disorders of blood vessels and surrounding tissue
RISK FACTORS
- Underlying bleeding disorders (e.g., von Willebrand disease, platelet dysfunction, thrombocytopenia)
- Child abuse/trauma
- Medications (aspirin, ibuprofen, cough syrups with guaifenesin, selective serotonin reuptake inhibitors [SSRIs])
- Infections
Genetics
- von Willebrand disease is the most common inherited bleeding disorder and is often autosomal dominant.
- Hemophilia is an X-linked disorder affecting males and some females.
- 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
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