(See also Overview of Vascular Bleeding Disorders.)
Purpura refers to purplish cutaneous or mucosal lesions caused by hemorrhage. Small lesions (< 2 mm) are termed petechiae, and large lesions are termed ecchymoses or bruises.
Purpura simplex is extremely common. The cause and mechanism are unknown. Purpura simplex may represent a heterogeneous group of disorders or merely a variation of normal.
Treatment with aspirin and oral anticoagulants (eg, warfarin), a low body weight, prior exposure to corticosteroids, and sun exposure may increase the risk of purpura simplex.
The disorder usually affects women. Bruises develop on the thighs, buttocks, and upper arms in people without known trauma. The history usually reveals no other abnormal bleeding, but easy bruising may be present in family members. Serious bleeding does not occur.
The platelet count and tests of platelet function, blood coagulation, and fibrinolysis are normal.
No drug prevents the bruising; patients are often advised to avoid aspirin and aspirin-containing drugs. Patients should be reassured that the condition is not serious. All patients should be evaluated for the possibility of physical abuse.