As might be expected from its different pathogenesis, angioedema seen in HAE does not respond to the drugs employed in treating other forms of urticaria/angioedema such as antihistamines, epinephrine, and corticosteroids. While epinephrine, in particular, may have a transient effect on swelling, it does not alter the course of an attack.
Maintaining airway patency is the primary concern for patients with laryngeal edema. If the airway is threatened, the patient should be intubated by an experienced physician. In addition, the capability for emergency tracheostomy should be readily available. Because gastrointestinal edema usually involves excruciating pain, frequent vomiting, and the potential for hypotension, therapy should include aggressive fluid replacement and pain management.
In the past, some physicians have used fresh frozen plasma in the acute attack setting, but this therapy is considered controversial because in addition to C1-inhibitor, fresh frozen plasma contains substrates of the complement and kinin systems that could produce a vasoactive peptide and cause an attack exacerbation.
TREATING CHILDREN WITH HAE
Fortunately, most prepubescent children with HAE do not suffer from frequent attacks and infrequent flares affecting the abdomen can be managed by using pain relievers and anti nausea agents. The small number of severely affected children who experience frequent and severe attacks must be managed on a case by case basis. Every physician will need to discern for him or herself how the approved medications may prove most useful for treating their young patients.
NEW TREATMENTS ON THE HORIZON
New HAE medicines are still being developed. At the moment, we know of around ten therapy candidates – among them single‑administration gene therapy treatments, orally-administered plasma kallikrein inhibitors, and humanized anti-factor XIIa monoclonal antibodies.