Telangiectasias on the Hand DR P MARAZZI / SCIENCE PHOTO LIBRARY Diagnosis of Hereditary Hemorrhagic Telangiectasia Clinical evaluation Sometimes endoscopy or angiography Sometimes genetic testing Diagnosis of hereditary hemorrhagic telangiectasia is based on the finding of characteristic arteriovenous malformations on the face, mouth, nose, palms, digits, and / or internal organs in the context of epistaxis and family history.