Suspected HHT in Primary Care: Next Steps and Referrals
Refer suspected HHT patients to an HHT Center of Excellence or multidisciplinary HHT specialist team for formal diagnosis using Curaçao criteria and immediate screening for life-threatening visceral arteriovenous malformations (AVMs) in the lungs, brain, and liver 1.
Immediate Actions in Primary Care
Apply the Curaçao Diagnostic Criteria
Assess for these four clinical features 1:
- Spontaneous, recurrent epistaxis (nosebleeds)
- Multiple telangiectasias on lips, oral mucosa, fingers, or face
- Visceral AVMs in lungs, liver, brain, or gastrointestinal tract
- First-degree family member with confirmed HHT
Diagnostic interpretation:
- 3-4 criteria = Definite HHT
- 2 criteria = Possible/suspected HHT
- <2 criteria = Unlikely HHT
Critical Referrals Required
For patients with definite or possible HHT, make these urgent referrals 1:
- HHT specialist center or multidisciplinary team - This is the primary referral that coordinates all subsequent care
- Screening for life-threatening AVMs must occur promptly:
Why This Matters for Morbidity and Mortality
The diagnostic delay in HHT is dangerously long 1, and unscreened visceral AVMs cause preventable catastrophic complications:
- Pulmonary AVMs → paradoxical embolic stroke, brain abscess, massive hemoptysis 2, 3
- Cerebral AVMs → intracerebral hemorrhage, seizures 3
- Hepatic AVMs → high-output heart failure, portal hypertension 1
Early detection through screening extends life expectancy to match the general population 4. Without screening, these complications are the primary drivers of mortality in HHT.
Genetic Testing Considerations
Genetic testing is recommended primarily for:
- Asymptomatic family members of confirmed HHT patients (allows early screening before symptoms develop) 1
- Patients with only 1-2 Curaçao criteria where diagnosis is uncertain 3
Genes involved: ENG (HHT type 1), ACVRL1 (HHT type 2), SMAD4 (juvenile polyposis-HHT overlap) - mutations detected in 97% of clinically definite cases 1, 5.
Additional Primary Care Management
While awaiting specialist evaluation:
Address iron deficiency anemia (present in nearly 50% of HHT patients) 6:
- Check CBC, iron studies, ferritin
- Initiate iron replacement if deficient
- Recognize that chronic epistaxis and GI bleeding drive this anemia 1, 7
Antibiotic prophylaxis: Patients with known or suspected pulmonary AVMs (or those not yet screened) require prophylaxis before dental procedures, endoscopy, or any procedure causing bacteremia - this prevents paradoxical brain abscess or embolic stroke 2.
Common Pitfalls to Avoid
- Don't dismiss recurrent epistaxis as "just nosebleeds" - this is the hallmark symptom in >90% of HHT patients and should trigger evaluation 4, 6
- Don't delay referral waiting for all four Curaçao criteria - two criteria warrant specialist evaluation 1
- Don't forget family screening - this is an autosomal dominant condition affecting 1 in 5,000 people; first-degree relatives need evaluation 1, 2
- Don't perform invasive procedures without considering pulmonary AVM screening first - undiagnosed pulmonary AVMs create stroke/abscess risk with bacteremia 2
The Otolaryngologist's Critical Role
Otolaryngologists managing refractory epistaxis serve as gatekeepers for HHT diagnosis 4. If you're referring for ENT management of recurrent nosebleeds, explicitly request HHT evaluation - this specialty can expedite the diagnostic pathway and initiate visceral AVM screening that prevents life-threatening complications 4, 8.