The four diagnostic criteria that HHT physicians use to determine if a person has HHT are known as the Curaçao Criteria
- If a doctor determines that at least three of these criteria are met, it is considered to be definite HHT.
- If two of the criteria are met, it is considered possible HHT.
- If less than two of these criteria apply, it is unlikely to be HHT.
The Curaçao Diagnostic Criteria for HHT
- Recurrent and spontaneous nosebleeds (epistaxis), which may be mild to severe.
- Multiple telangiectases on the skin of the hands, lips or face, or inside of the nose or mouth. Telangiectases are small red spots that disappear when pushed on.
- Arteriovenous malformations (AVMs) or telangiectases in one or more of the internal organs, including the lungs, brain, liver, intestines, stomach, and spinal cord.
- A family history of HHT (i.e. first-degree relative such as brother, sister, parent or child who meets these same criteria for definite HHT or has been genetically diagnosed).
Sometimes a physician is not able to make a definitive clinical diagnosis based on the above criteria alone.
In these cases, a genetic test might help determine if they have HHT:
- A positive genetic test would confirm that someone does have HHT.
- A negative test does not rule out HHT. 15% of people with HHT have mutations in genes that are not yet identified HHT genes.
A few features of the diagnostic criteria:
- The criteria spell out in detail what is required for each manifestation for it to be considered HHT. For example, since there is no agreement among doctors about the precise number of episodes or severity of nosebleeds needed to satisfy a diagnosis of HHT, the criteria merely highlight that to be considered a symptom of HHT, nosebleeds should occur spontaneously on more than one occasion, with night-time bleeds being particularly suspicious.
- The criteria stresses the importance of taking a detailed and targeted family history in order to establish the diagnosis of this disorder in an individual. When someone has the HHT genetic mutation it is very likely that they will experience symptoms, but the symptoms of HHT can vary a lot between individuals, even within the same family. These criteria also allow doctors to distinguish between individuals who definitely have HHT, and those in whom it is suspected, ensuring appropriate follow-up and medical management.
- The criteria emphasizes that all children of an individual with HHT are at risk of having the disease. It is recommended that if there is any concern regarding the presence or absence of physical signs, a physician experienced with HHT should be consulted.
Knowing your family's medical history can save a life!
The Surgeon General launched a national initiative to encourage all American families to learn more about their family health histories. This online tool will help you to organize your family tree and identify the health disorders that may have moved from one generation of your family to the next. The finished product will provide a graphical representation of the health of each generation of your family and is especially important for HHT families as you begin to record and understand your family’s medical histories.