This chapter discusses purpura and bruising, terms used to describe bleeding into the skin, which may occur as isolated phenomena or as part of a systemic disorder. Clinically, purpura can represent vasculitis affecting small vessels of the skin, or may be the minor or dominant features of a systemic vasculitis. Many platelet and coagulation disorders seen by haematologists present with purpura. Purpuric lesions may be seen in disorders such as vasculitis, presenting as urticarial lesions, nodules, ulcers, livedo and skin necrosis. These signs often occur in disorders where vessels are occluded. The epidemiology, pathophysiology, clinical features, differential diagnosis and management of purpura and bruising due to different causes are discussed.
Keywords purpura, bruising, capillaritis, thrombocytopenia, coagulation, platelet, microvascular, thrombotic, vasculitis, urticarial lesions