Studies suggest that 50% of people with HAE report their first symptoms by the age of 10 and most people have experienced symptoms/their first attack before age 18.

Although there are exceptions, HAE symptoms are usually mild in young children, however, attacks have been reported in children as early as 1 year of age. The frequency and severity of HAE attacks may increase during puberty and adolescence.

Attacks can be spontaneous, or caused by a trigger.

Common causes of HAE attacks: 

  • Anxiety

  • Stress

  • Minor trauma

  • Surgery

  • Sickness such as cold or flu

  • Typing

  • Prolonged writing

  • Pushing a lawn mower

  • Hammering & Shovelling

  • Exposure to cold


Dental Procedures

ACE Inhibitors

In women, menstruation and pregnancy are reported to have a major effect on disease activity. Some female patients report a definite increase in the number of attacks during their menstrual periods, pregnancy, or while breast feeding.

Use of estrogen-derived medicines, such as oral contraceptives and hormone replacement therapy, are also associated with an increase in frequency and severity of HAE attacks.

Patients should consult with their HAE treating physician regarding alternative, non-estrogen, birth control options.

Trauma to the mouth caused by dental procedures can increase patients’ vulnerability to airway attacks. Patients should confer with their HAE treating physician before undergoing dental procedures.

Often used to treat high blood pressure, ACE Inhibitors have been known to increase the frequency and severity of HAE attacks. Please consult your HAE treating physician if you are currently taking an ACE Inhibitor or any other drugs that might affect your HAE symptoms.