Bleeding may result from abnormalities in
Blood vessels
Vascular bleeding disorders result from defects in blood vessels, typically causing cutaneous or mucosal lesions called petechiae, purpura, and ecchymoses depending on their size but, except for hereditary hemorrhagic telangiectasia, seldom leading to serious blood loss. Small lesions (< 2 mm) are termed petechiae, and larger lesions are termed purpura if they are > 2 mm and <10 mm or ecchymoses if > 10 mm.
Bleeding may result from deficiencies of vascular and perivascular collagen in Ehlers-Danlos syndrome and in other rare hereditary connective tissue disorders (eg, pseudoxanthoma elasticum, osteogenesis imperfecta, Marfan syndrome).
Hemorrhage may be a prominent feature of scurvy or of immunoglobulin A–associated vasculitis, a hypersensitivity vasculitis common during childhood.
In vascular bleeding disorders, results of tests of hemostasis are usually normal. For most disorders, diagnosis is clinical; specific tests are available for some (eg, immunoglobulins in specific dysproteinemias).
Treatment focuses on controlling the bleeding when possible and providing supportive care. Some patients require blood transfusions. Many patients require iron therapy to replace iron lost due to repeated mucosal bleeding (see treatment of Iron Deficiency Anemia).
