How is Hereditary Hemorrhagic Telangiectasia diagnosed?

Hereditary Hemorrhagic Telangiectasia (HHT), also known as Osler-Weber-Rendu syndrome, is primarily diagnosed using the clinical Curaçao Criteria, which assess symptoms like recurrent nosebleeds, telangiectasias, and visceral organ involvement. While genetic testing can confirm the diagnosis by identifying mutations in genes such as ENG, ACVRL1, or SMAD4, a diagnosis can often be established clinically by a specialist even without genetic confirmation.

How is Hereditary Hemorrhagic Telangiectasia diagnosed?

The diagnostic process for Hereditary Hemorrhagic Telangiectasia often begins with a thorough clinical examination. Physicians look for specific physical markers, most notably telangiectasias—small, spider-like blood vessel dilations—on the lips, tongue, fingertips, or inside the nose. Because HHT can manifest differently even within the same family, the diagnostic journey can be complex. Many patients experience a "diagnostic odyssey," often waiting years for an accurate diagnosis because symptoms like recurrent nosebleeds (epistaxis) are frequently dismissed as minor or unrelated to a systemic vascular condition.

What are the Curaçao Criteria?

To standardize the diagnosis of Hereditary Hemorrhagic Telangiectasia, clinicians use the validated Curaçao Criteria. A diagnosis is considered "definite" if a patient meets three or more of the following criteria, "possible" if two are met, and "unlikely" if fewer than two are present:

• Spontaneous, recurrent nosebleeds (epistaxis): The most common early symptom.


• Multiple mucocutaneous telangiectasias: Typically found on the lips, oral cavity, fingers, or nose.


• Visceral lesions: Documented involvement of organs such as the lungs, liver, brain, or gastrointestinal tract (e.g., arteriovenous malformations).


• Family history: A first-degree relative who has been diagnosed with Hereditary Hemorrhagic Telangiectasia according to these criteria.

What tests and specialists are involved?

Diagnosis is usually managed by a multidisciplinary team, including hematologists, geneticists, and pulmonologists. Beyond the clinical evaluation, imaging plays a critical role in detecting "silent" vascular malformations. Physicians may order a bubble echocardiogram to screen for pulmonary arteriovenous malformations (PAVMs), or MRI/CT scans to check for brain or liver involvement. Genetic testing is highly recommended to confirm Hereditary Hemorrhagic Telangiectasia and to facilitate cascade screening for other family members, as the condition is autosomal dominant.

What conditions can be confused with HHT?

Because the clinical presentation varies, Hereditary Hemorrhagic Telangiectasia is sometimes misdiagnosed as other vascular or bleeding disorders. Differential diagnoses may include Von Willebrand disease, benign hereditary telangiectasia, or other forms of pulmonary hypertension. We understand how isolating it feels to be misdiagnosed; if your current medical team is not familiar with Hereditary Hemorrhagic Telangiectasia, it is vital to seek a referral to a dedicated HHT Center of Excellence. Early detection of visceral malformations can prevent life-threatening complications, making expert consultation essential.

Next steps

• Consult a specialized HHT Center of Excellence for a comprehensive evaluation.


• Request a referral to a clinical geneticist to discuss testing for yourself and your family members.


• Join our community at DiseaseMaps.org to connect with 141 other individuals who have navigated the diagnosis of Hereditary Hemorrhagic Telangiectasia.


• Keep a detailed log of your symptoms, specifically tracking the frequency and severity of nosebleeds and any family history of vascular issues.

Medical disclaimer: This content is for informational purposes only and does not constitute medical advice, diagnosis, or treatment; always seek the advice of your physician or other qualified health provider with any questions regarding a medical condition.

References

• NIH Genetic and Rare Diseases Information Center (GARD): Hereditary Hemorrhagic Telangiectasia.


• Orphanet: Rare Disease Database (ORPHA:774).


• OMIM (Online Mendelian Inheritance in Man): Entry #187300 (HHT1).


• Cure HHT (HHT Foundation International): Diagnostic Guidelines and Patient Resources.