Sir, I would like to thank Dr Raval for shedding light on a life-threatening acute angioedema in his article.1

The prolonged use of medications (biphosphonates, warfarin, immunosupressors, anxiolytics and psychotropic drugs, angiotensin converting ensyme – ACE) is becoming more and more common, and dental practitioners may frequently face dilemmas related to the increased risk of medical emergencies in dental practice.

General management of dental patients with a history of ACE use (hypertension, heart failure) may require additional investigations before undergoing routine dental treatment. Dentists should consider asking all patients if they have a history of unexplained skin swelling as part of their routine history. On the other hand, dentists may play a crucial role in helping to establish a potentially lifesaving diagnosis, in the case of suspecting symptoms of congenital C1-esterase inhibitor deficiency and hereditary angioedema (HAE).2

In patients with diagnosed HAE, a short-term pharmacological prophylaxis with the use of C1 esterase inhibitor is a viable option before dental treatment in patients with existing hereditary angioedema. Human C1 esterase inhibitor (C1-INH), registered in the UK under brand name Berinert (CSL Behring Ltd) can be administered not only for emergency treatment in case of acute head and neck angioedema but also as a pre-procedure prevention of acute episodes of hereditary angioedema type I or II.3 According to the UK Monthly Index of Medical Specialities: 'pre-procedure dental or medical prevention should be done with the use of 1,000 units within six hours before medical, dental or surgical procedure by slow intravenous injection or infusion in hospital setting'. However, according to the US Food and Drug Association agency, the safety and efficacy of Berinert for prophylactic therapy has not been established.4

Berinert is made from human blood, and hence it may contain infectious agents (eg viruses and, theoretically, the Creutzfeldt-Jakob disease [CJD] agent – prions). This risk has been considerably reduced to minimum by screening plasma donors, by testing for the presence of certain current virus infections, and by specific processes in order to inactivate and/or remove certain agents during manufacturing.

When considering a prophylactic injection/infusion with C1 esterase inhibitor before dental treatment, when there is a risk of angioedema onset in patients with HAE, informed consent should be obtained following thorough explanations. The physician should discuss the risks and benefits of this product with the patient before prescribing or administering it.