Hereditary Angioedema: Causes, Symptoms, and Treatment Options

When dealing with hereditary angioedema, a rare genetic disorder that causes sudden, painful swelling in the skin and mucosal tissues. Also known as HAE, it often stems from a deficiency or dysfunction of C1 inhibitor, a protein that regulates the complement and contact systems, leading to excess bradykinin, a peptide that increases vascular permeability and triggers swelling. The condition follows an autosomal dominant inheritance pattern, so a single mutated gene can pass the risk to children. Because the swelling can affect the throat, abdomen, or limbs, recognizing the early signs can be lifesaving.

The complement system, a cascade of proteins that helps the immune system clear pathogens is tightly linked to HAE. When C1 inhibitor is missing or faulty, uncontrolled activation of the complement pathway and the kallikrein-kinin system occurs, flooding the body with bradykinin. This biochemical chain‑reaction is the root cause of the episodic swelling. Triggers such as stress, hormonal changes, minor injuries, or certain medications can tip the balance, prompting an attack within minutes. Understanding that HAE attacks are a result of a cascade—not an allergic reaction—helps patients avoid unnecessary antihistamines or steroids, which are ineffective against bradykinin‑driven swelling.

Understanding Triggers and Modern Treatments

Because the swelling is bradykinin‑mediated, treatment strategies focus on either replacing the missing inhibitor or blocking the downstream effects. The first line of defense is C1 inhibitor replacement therapy, available in plasma‑derived or recombinant forms. Regular prophylactic infusions keep the inhibitor levels high enough to prevent most attacks, while on‑demand doses can halt an episode that’s already started. For patients who prefer oral medication, kallikrein inhibitors like lanadelumab interfere with the enzyme that generates bradykinin, offering long‑acting protection with just a monthly injection. Another option is a bradykinin receptor antagonist such as icatibant, which blocks the B2 receptor and provides rapid relief when administered during an attack.

Beyond medication, lifestyle adjustments play a big role. Keeping a symptom diary helps identify personal triggers—maybe a particular exercise routine or a hormonal birth control method. Staying hydrated, managing stress through mindfulness or light exercise, and avoiding known risky medications (like ACE inhibitors) can reduce the frequency of attacks. Some patients also benefit from dental work done under short‑term C1 inhibitor cover to prevent swelling of the mouth and throat.

Family screening is another crucial piece. Since HAE is inherited, testing first‑degree relatives can catch the disorder before the first painful episode occurs. Early diagnosis means early access to prophylaxis, which dramatically improves quality of life. Genetic counseling can guide families on the chances of passing the mutation to the next generation, helping them make informed decisions.

Below you’ll find a curated collection of articles that dive deeper into specific drugs, diagnostic tools, and patient experiences related to hereditary angioedema. Whether you’re looking for a comparison of C1 inhibitor products, tips on managing abdominal attacks, or the latest research on novel bradykinin blockers, the posts ahead cover the breadth of information you need to stay ahead of the condition.