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Quincke's Edema (Hereditary Angioedema)

Overview

Quincke’s edema, more commonly called hereditary angioedema (HAE), is a rare genetic disorder that causes recurrent episodes of severe swelling (angioedema) in various parts of the body. The swelling is due to excess bradykinin, a peptide that makes blood vessels leaky, rather than histamine, which differentiates HAE from typical allergic reactions.

• Who it affects: Both males and females; symptoms can appear at any age, often in childhood or early adolescence.
• Prevalence: Approximately 1 in 50,000 – 1 in 100,000 people worldwide have HAE (World Allergy Organization, 2022). About 25 % of cases are de‑novo mutations, meaning no family history is present.

Symptoms

Symptoms vary in frequency and severity, and an individual may experience only some of the following:

Typical Angioedema Attacks

• Peripheral edema: Swelling of the hands, feet, arms, legs, or genitalia. The skin appears smooth, warm, and non‑itchy.
• Facial swelling: Involves lips, tongue, eyelids, or cheeks; can cause difficulty speaking.
• Abdominal attacks: Severe abdominal pain, nausea, vomiting, and bowel wall edema that may mimic an acute surgical abdomen. Diarrhea or constipation can accompany the pain.
• Upper airway edema: Swelling of the larynx, pharynx, or tongue; can rapidly progress to life‑threatening airway obstruction.

Additional Features

• Attacks last 2‑5 days if untreated.
• No urticaria (hives) or itching, which helps distinguish HAE from allergic angioedema.
• Prodromal sensations such as tingling, itching, or a “tight” feeling may precede swelling.
• Stress, trauma, hormonal changes (especially estrogen), and certain medications (e.g., ACE inhibitors) can trigger attacks.

Causes and Risk Factors

Genetic Basis

HAE is an autosomal‑dominant disorder caused by mutations in the C1‑INH gene (SERPING1). There are three main types:

1. Type I (≈85 %): Low levels of functional C1‑inhibitor protein.
2. Type II (≈15 %): Normal quantity but dysfunctional C1‑inhibitor.
3. Type III (also called HAE with normal C1‑INH): Mutations in genes such as FXII, PLG, or ANGPT1. Often estrogen‑dependent and more common in women.

Risk Factors

• Family history: A first‑degree relative with confirmed HAE raises risk dramatically.
• Female sex: Hormonal fluctuations can increase attack frequency.
• Exposure to ACE inhibitors or ARBs: These drugs inhibit bradykinin breakdown, precipitating swelling.
• Physical or emotional stress, dental procedures, surgery, or dental work.

Diagnosis

Because HAE mimics many other conditions, a systematic approach is essential.

Clinical Evaluation

• Detailed personal and family history of recurrent, non‑itchy swelling.
• Exclusion of allergic, infectious, or autoimmune causes.

Laboratory Tests

1. C4 complement level: Usually low during and between attacks; a sensitive screening test.
2. C1‑inhibitor quantitative assay: Measures protein concentration (low in Type I).
3. C1‑inhibitor functional assay: Assesses activity (low in Type II and some Type III cases).
4. Genetic testing: Sequencing of SERPING1 and, if needed, other HAE‑associated genes (FXII, PLG, etc.) confirms diagnosis, especially for normal‑C1‑INH HAE.

Imaging (when necessary)

• Abdominal CT or ultrasound during an abdominal attack can reveal bowel wall edema, helping to rule out other acute abdomen causes.

Diagnostic Criteria (per WAO 2023)

• Recurrent angioedema without urticaria, plus low C4 and either low C1‑INH level or low functional activity, or a confirmed pathogenic SERPING1 mutation.

Treatment Options

Therapy focuses on three goals: aborting acute attacks, short‑term prophylaxis before known triggers, and long‑term prophylaxis to reduce attack frequency.

Acute Attack Management

• C1‑esterase inhibitor concentrate (plasma‑derived or recombinant): 20 U/kg IV (e.g., Berinert, Ruconest). Most effective when given within the first 2 hours.
• Bradykinin‑B2 receptor antagonist – Icatibant (Firazyr): 30 mg subcutaneously; repeat dosing if needed after 6 hours.
• Lanadelumab (Takhzyro) – a monoclonal antibody against plasma kallikrein: Used for both acute treatment (off‑label) and prophylaxis.
• Supportive care: airway monitoring, oxygen, IV fluids for abdominal attacks.

Short‑Term (Pre‑Procedural) Prophylaxis

• Administer C1‑INH concentrate 1‑2 hours before dental or surgical procedures.
• Or‑al tranexamic acid (1,000 mg 3 times daily) for patients who cannot receive IV C1‑INH.

Long‑Term Prophylaxis

Medication	Mechanism	Typical Dose	Key Points
Lanadelumab (Takhzyro)	Kallikrein inhibitor	300 mg SC every 2 weeks (can be extended to every 4 weeks)	Highly effective; injectable; FDA‑approved 2018.
Berotralstat (Orladeyo)	Kallikrein inhibitor (oral)	150 mg once daily	First oral prophylactic; monitor liver enzymes.
Plasma‑derived C1‑INH (Cinryze)	Replaces deficient inhibitor	1000 U IV twice weekly	Effective but requires regular IV access.
Antifibrinolytics (tranexamic acid, epsilon‑aminocaproic acid)	Reduce bradykinin generation	Tranexamic acid 1,000 mg 2‑3×/day	Less potent; useful in pregnancy.

Lifestyle & Adjunct Measures

• Carry an emergency “HAE kit” with C1‑INH concentrate or icatibant.
• Avoid ACE inhibitors, estrogen‑containing oral contraceptives, and angiotensin‑receptor blockers.
• Maintain a symptom diary to identify personal triggers.

Living with Quincke's edema (hereditary angioedema)

Daily Management Tips

• Medication adherence: Set reminders for prophylactic doses; missing a dose can increase attack risk.
• Stress reduction: Practice relaxation techniques (deep breathing, yoga, mindfulness) as stress is a common trigger.
• Dietary considerations: No specific diet is required, but avoid foods that have previously preceded attacks.
• Travel preparation: Pack enough medication for the entire trip plus extra; keep it in a temperature‑controlled bag and carry a copy of the prescription.
• Education: Inform family, friends, coworkers, and school staff about the condition and how to administer emergency medication.
• Dental care: Notify the dentist of HAE; receive pre‑procedure C1‑INH prophylaxis.
• Pregnancy: Discuss prophylaxis options with an obstetrician; C1‑INH concentrate is considered safe, while some oral agents are not.

Support Resources

National organizations such as the HAE Association, the HAE UK, and local patient groups provide education, counseling, and emergency‑plan templates.

Prevention

• Medication review: Ensure no ACE inhibitors or estrogen‑containing products are prescribed.
• Vaccinations: Keep up‑to‑date (e.g., influenza, COVID‑19) to reduce infection‑related stress.
• Trigger avoidance: Use a diary to spot patterns—e.g., specific foods, temperature extremes, or intense exercise.
• Prophylactic dosing: Consistent long‑term prophylaxis dramatically cuts attack frequency (up to 90 % reduction with lanadelumab).

Complications

If HAE is not properly managed, several serious complications may arise:

• Airway obstruction: Laryngeal edema can cause rapid respiratory failure; accounts for 10‑15 % of HAE‑related deaths.
• Abdominal emergencies: Repeated bowel wall edema may lead to obstruction, perforation, or unnecessary surgeries.
• Psychological impact: Chronic unpredictability can cause anxiety, depression, and reduced quality of life.
• Medication‑related side effects: Long‑term C1‑INH therapy may cause rare anaphylaxis; antifibrinolytics can affect renal function.

When to Seek Emergency Care

References

1. World Allergy Organization (2022). Hereditary Angioedema Consensus Guidelines.
2. Mayo Clinic. Hereditary angioedema (HAE). https://www.mayoclinic.org/diseases-conditions/hereditary-angioedema
3. National Institute of Allergy and Infectious Diseases (NIAID). Hereditary Angioedema. https://www.niaid.nih.gov/diseases-conditions/hereditary-angioedema
4. Cleveland Clinic. Hereditary Angioedema Treatment Options. https://my.clevelandclinic.org/health/diseases/21213-hereditary-angioedema
5. U.S. Food & Drug Administration (2023). FDA approves lanadelumab (Takhzyro) for prophylaxis of HAE.
6. European Academy of Allergy and Clinical Immunology (EAACI) Position Paper on HAE, 2021.

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