Disease-related bruising and migration of extravasated blood
THE CONTEXT
Disease can increase bruising after minimal force, and blood tracking through tissues can produce visible bruises away from the site of injury.
Disease and easy bruising
•
Diseased vessels in arteriosclerosis may permit bruising after coughing or slight exertion. Violent coughing in children, as in whooping cough, can cause small bruises.
•
Prominent bruising after minor trauma occurs in purpura haemorrhagica, leukaemia, haemophilia, scurvy, vitamin K deficiency, prothrombin deficiency and phosphorus poisoning.
•
Purpuric areas have clearly delineated margins and never show swelling.
•
Older people, especially those taking systemic steroids, may develop senile ecchymoses, particularly on the extremities, after little force or spontaneously.
Ectopic or migratory bruising
•
A deep bruise can take a long time to become visible and need not appear at the point of impact.
•
Blood tracks along fascial planes or between muscle layers and may become visible where those layers become superficial. This is described as ectopic, percolated or migratory contusion.
•
The location of a visible bruise does not always identify the location of the violence.
Examples of displaced bruising
•
A black eye or spectacle haematoma may follow direct trauma, a forehead impact with downward tracking of blood, or fracture of the floor of the anterior cranial fossa.
•
Bruising behind the ear may indicate a basal fracture and is described as Battle's sign.
•
Jaw fracture may produce neck bruising; pelvic fracture may produce thigh bruising; femoral fracture may produce bruising on the outer side of the lower thigh.
•
A blow to the upper thigh may produce a bruise above the knee, while a kick to the calf may produce a bruise around the ankle.