Ecchymosis: A term used to describe discoloration that results in a dark bluish-red patch more than one centimeter in diameter. Although many sources refer to any bruising of the skin, such as caused by contusion, as ecchymosis, this is probably a misuse of the term. It should perhaps be distinguished from discoloration resulting from a direct trauma/contusion, although all sources do not agree.
Ecchymosis is an accumulation of blood in the skin and subcutaneous tissues that is caused by blood moving from one extravascular space to another. This movement is caused by a medical or hematological condition, or indirectly caused by trauma.
Such movement of blood is called extravasion. An example is the appearance of black eyes caused by a blow to the mid-forehead right above the nose.
Although the trauma does not occur directly to the eye or orbital area, the trauma to the forehead allows blood to seep down to the peri-orbital areas. On the other hand, when a person is punched directly in the eye, not only is there discoloration which should be called bruising, there is also swelling and pain in the eye.
This discoloration resulting from blood donation, we would
normally called bruising. But it is more technically ecchymosis.
The appearance of skin bruising near the area of a muscular strain can also be called ecchymosis. This type of discoloration can appear to be quite widespread and irregular due to the blood drifting inferiorly due to gravity. The size of the discolored area, therefore, does not necessarily denote the extent of the damage. Notice, in the image below, that although the muscle strain occurred in the hamstring of the posterior thigh, there is also ecchymosis in the calf area of the lower leg. This may be due to the blood having seeped downwards rather than indicating a strain in that area.
Ecchymosis from a pulled hamstring.
Note that there is discoloration in the thigh
and the calf area.
image by Daniel.Cardenas via wikimedia
Periorbital ecchymosis, as has been described, is sometimes called raccoon eyes and the appearance of raccoon eyes, after a head trauma, can be used to pre-diagnose a skull fracture, as can the Battle's sign which is ecchymosis of the area behind the ear, indicating a fracture of the base of the skull.
This type of hemorrhagic blotching of the skin is more prevalent in elderly skin and clotting and bleeding disorders can also cause ecchymosis.
Similar to bruising, ecchymosis starts out as a bluish looking lesion but the colors change as the red blood cells progressively degenerate. Usually the blue changes to a green, to a purple, and finally to a brownish-yellow color before fading away. The lesions are usually not painful and are not hard or firm to the touch (nonindurated).
This page created 27 Sep 2012 19:54
Last updated 01 Mar 2016 19:02