Hereditary Angioedema Type I Triggered by Dental Treatment: A Case Report and Review of the Literature

Hereditary angioedema (HAE) is a condition presenting with recurrent episodes of severe swelling affecting the mucosa of the respiratory and gastrointestinal tracts and skin.¹ Commonly, the lips, hands, arms, gastrointestinal tract and upper airway are affected. Swelling of the respiratory tract can lead to life-threatening consequences as a result of obstruction caused by laryngeal oedema. Early diagnosis is therefore critical.² The aetiology is attributed to a mutation in the SERPING1 gene, which is responsible for the production of C1 esterase inhibitor (C1-INH), an acute-phase reactant and a member of the ‘serpin’ superfamily of serine protease inhibitors.² Type 1 HAE (accounting for 85% of C1INH-HAE) is associated with a reduced quantity of C1-INH, while type 2 HAE is associated with the production of dysfunctional C1-INH.² This results in an excessive production of bradykinin, a potent vasodilatory mediator with vascular permeability-enhancing effects. It is prevalent in approximately 1 in 50,000 people.² The inheritance of types I and II HAE is autosomal dominant; however, approximately 25% of cases result from de novo mutations, so a positive family history is not required for diagnosis.³ The risk of mortality may be as high as 30%; however, if precipitants are avoided or the emergency is effectively treated, the disease is compatible with prolonged survival.⁴