What is the likelihood of dental work triggering an HAE attack?

Aug 24, 2015

“My daughter has tested positive for HAE type II. She has not had any issues to date but needs dental work done. They want to infuse her first. Can infusing for precautions trigger attacks to start?”

Dr. C: This is a question within a question. The first is what is the likelihood of dental work triggering an attack of swelling? There is a common assumption that all dental work will trigger an episode of swelling. Back in the day when no acute therapy was available we would routinely recommend FFP or short courses of androgen for prophylaxis with variable success. Because of the risk of an airway attack, pre-procedure prophylaxis was considered to be essential. So while we measure how often patients swelled despite pre-treatment, we didn’t know how high the risk of swelling was. With the availability of on-demand treatments for angioedema attacks, however, it has become possible to study this question. Konrad Bork reported on exactly this in a 2011 paper. Could you review his results, Bruce?

Dr. Z: Certainly. Dr. Bork looked at tooth extractions in a large group of patients with HAE who were either given pre-treatment with C1 inhibitor or were not pre-treated. One hundred and forty-eight patients underwent at least one dental extraction without receiving C1 inhibitor prophylaxis. Among these 148 patients, 55 experienced swelling of the face or airway and 93 had no swelling following the procedure. Some of the patients underwent multiple extractions without prophylaxis. When he asked what percentage of extractions in patients without prophylaxis resulted in swelling, the answer was 21%, or slightly more than a 1 in 5 chance. Among the 171 patients who did receive C1 inhibitor prophylaxis, 20% experienced a swelling episode. Again, when he looked at the risk per extraction, it was 12% in the C1 inhibitor treated group, or a little less than 1 in 8 chance. One last point is that the dose of C1 inhibitor mattered. Patients receiving 500 units of C1 inhibitor had swelling 16% of the time, but this dropped to 7.5% of the time in those who received 1,000 units of C1 inhibitor.

Dr. C: Thank you. I think that it is also important to comment on the timing of the swelling attacks following the extractions. Most of the attacks did not occur right away,and in fact the earliest attack was 4 hours after the procedure. Overall the average time from extraction to swelling was 8.4 hours. In those who didn’t receive prophylaxis, the average time lag was 14.3 hours. The time lag was shorter for those who received prophylaxis. This translates into a need for vigilance for the night after the procedure.

As to the second question posed by our reader I am not aware of any data that infusing with C1 inhibitor in an asymptomatic subject has induced an attack. Marc, are you aware of any reports? Also given Konrad Bork’s data what are you recommending for your patients for dental procedures?

Dr. R: This interesting question raises a couple of important issues.  Regarding the specific question, there’s no evidence currently that using HAE specific medication, such as C1INH concentrate, will trigger attacks to start in an otherwise asymptomatic person with C1-INH deficiency.   On the other hand, medical procedures such as dental work are known to trigger attacks in some patients.  This is one of the reasons family testing is strongly encouraged even in family members without symptoms – in order to be prepared for these potential triggering events.  The response to dental work is highly variable in HAE. Routine teeth cleaning or cavity filings generally don’t cause any angioedema problems, but in certain patients may trigger attacks.  More extensive dental work like oral surgery and tooth extractions are higher risk – studies suggest these procedures will trigger angioedema attacks in 20-40% of individuals with HAE. Short-term prophylactic treatment with C1INH-concentrate is often recommended prior to these procedures to maximize safety, though that’s a decision to be made between the patient and their HAE specialist.  Whether short term-prophylaxis is used or not, it’s essential to have acute HAE medication readily available to treat any swelling that occurs with or following the dental work.  These attacks can sometimes happen 1-2 days after the procedure.  All of this is manageable and should not prevent recommended dental work, but it’s vitally important for the dentist, HAE specialist, and patient to communicate and collaborate so that the plan of care can run smoothly and safely.

Dr. C:  Thank you, Bruce and Marc. This was an important topic for all with HAE—preparation to ‘share our smiles’ on our next HAE day. We look forward to our next ‘Question of the Week’.

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