Clinical Diagnosis Criteria
The established diagnostic criteria for HHT are:
- Nosebleeds (epistaxis), which are spontaneous and recurrent, may be mild or severe
- Telangiectases on the skin or mucous membranes(mucocutaneous). Telangiectases are small red spots that blanch under pressure, located at characteristic sites, including the lips, oral cavity, fingers, and nose.
- Visceral arteriovenous malformations (AVMs) consisting of direct connections between arteries and veins. They may be located in the lungs, brain, liver, spinal cord, or GI tract.
- A first-degree relative (brother, sister, parent or child) with HHT, based on these diagnostic criteria.
A diagnosis of HHT is considered definite when 3 or more of these features are present, possible or suspected when 2 findings are present, and unlikely with fewer than 2 findings.