Previous studies of the mechanism of bleeding in hereditary hemorrhagic telangiectasia (HHT) suggest the presence of a local hemostatic abnormality. As the fibrinolytic system is an integral part of the local hemostatic function, the plasminogen activator content of the telangiectatic lesion was studied. Skin and nasal mucosal biopsied specimens were examined by a histochemical fibrin slide method for fibrinolytic activity. The dilated telangiectatic small vessel consistently showed an increase in plasminogen activator. Such findings suggest a role of fibrinolysis in the bleeding. The topical application of aminocaproic acid, an inhibitor of fibrinolysis, effectively arrested epistaxis.
Kwaan HC, Silverman S. Fibrinolytic Activity in Lesions of Hereditary Hemorrhagic Telangiectasia. Arch Dermatol. 1973;107(4):571-573. doi:10.1001/archderm.1973.01620190047011