In this section
(Hereditary Angioedema, HAE)
HAE causes recurrent episodes of angioedema in the upper
respiratory, gastrointestinal tract or in subcutaneous tissues.
Acute episodes of angioedema may be triggered by infection,
stress, menstruation, surgery, dental work, trauma and some
medicines (including oestrogen-containing contraceptives and
ACE-inhibitors) or may have no clear trigger.
HAE is a rare autosomal dominant condition in which C1 esterase
inhibitor levels are reduced (HAE type I) or poorly functional (HAE
type II). HAE is diagnosed by the finding of low C1 esterase
inhibitor level or function. C4 level is also low during episodes
Clinical features include:
Angioedema episodes usually take several hours to develop, and
if untreated last 1-5 days.
Treatment is conservative:
Severe angioedema episodes can be fatal. Management
Surgery or any traumatic procedure of the oropharyngeal area
such as dental work should be carefully planned. The use of a
prophylactic agent prior to such procedures reduces the risk of
Antihistamines and corticosteroids have no role in the
management of HAE related angioedema. The role of adrenaline in the
treatment of HAE is not well established. There are anecdotal
reports of efficacy using nebulised or intramuscular adrenaline to
treat upper airway angioedema, however C1 esterase inhibitor is the
treatment of choice for airway angioedema caused by HAE.
This is not TGA approved, and approval is required to use it on
an individual patient basis. Consultation with the on-call
immunologist is important. 25 units/kg (rounded to nearest 500
units) is infused over 1-2 minutes. 70% of angioedema episodes
respond within 30 minutes of infusion, and 95% within 4 hours. If
there is no response within 4 hours alternative diagnoses should be
considered, but the dose may be repeated at this stage after
further discussion with the on-call immunologist.
One vial is kept in the Emergency Department vaccine fridge, and
2 spare vials in RCH pharmacy. If RCH stock is exhausted, emergency
supplies may be obtained from the on-call pharmacist at the Royal
Melbourne Hospital, or from CSL Blood Division. Each time Berinert
is used, a Special Access Scheme (SAS) form must be completed by
the prescribing physician.