Confirming the Disease Name
Angioedema — the medically accurate term in widespread use.
1) Disease Description (Causes and Symptoms)
- Definition and pathophysiology: A condition in which increased vascular permeability in the deep layers of the dermis and subcutaneous tissue (or mucosa) causes localized, non-tender swelling. The pathophysiology is broadly divided into two mechanisms.
- Histamine-mediated (immune or nonimmune): Caused by histamine and inflammatory mediators released from mast cells or derived from mast cells, which increase vascular permeability (such as allergic or drug-induced angioedema). Urticaria may occur concurrently.
- Bradykinin-mediated: Caused by bradykinin accumulation due to C1 esterase inhibitor (C1-INH) deficiency (hereditary angioedema, HAE) or ACE inhibitor use. It generally lasts longer without itching or urticaria and responds poorly to antihistamines or steroids.
- Major causes: Allergies (food, insect venom, medications, latex, etc.), certain medications (especially ACE inhibitors), hereditary causes (HAE; C1-INH deficiency or reduced function), and primary or idiopathic causes.
- Typical symptoms: Sudden swelling of the face, lips, area around the eyes, extremities, or neck; difficulty breathing due to swelling of the tongue or larynx (an emergency); abdominal cramps, vomiting, or abdominal pain (when the intestinal mucosa is involved). Attacks may last from several hours to several days.
Urgent warning signs: Difficulty breathing, voice changes (hoarseness), swelling of the tongue or throat, or reduced consciousness — immediate emergency treatment is required.
2) Treatment Methods and Precautions
- Initial (emergency) response
- Check the airway, breathing, and circulation. If airway obstruction is suspected, go to the emergency room immediately (airway protection, endotracheal intubation, etc.).
- If anaphylaxis is suspected, immediately administer intramuscular (IM) epinephrine (the recommended site is the outer thigh), oxygen, IV fluids, and airway management.
- Drug treatment (depending on the cause)
- Histamine-mediated type (allergic)
- H1 antihistamines (oral or intravenous); an H2 blocker may be used in combination, and systemic corticosteroids may be used in severe cases.
- Epinephrine takes priority in anaphylaxis.
- Bradykinin-mediated type (HAE or ACE inhibitor-induced)
- It often does not respond to antihistamines, steroids, or epinephrine.
- Specific treatments: C1 esterase inhibitor (C1-INH) concentrate (intravenous), icatibant (a bradykinin B2 receptor antagonist; subcutaneous injection), and ecallantide (a kallikrein inhibitor; when available). When specific agents are unavailable, fresh frozen plasma (FFP) may be considered.
- When ACE inhibitor-induced: Discontinue the medication in question (use an alternative antihypertensive medication).
- Histamine-mediated type (allergic)
- Prevention (long-term management)
- Avoid known triggers (allergens, specific medications, etc.).
- Hereditary angioedema: Consider preventive medications (regular C1-INH replacement, biologic agents such as lanadelumab, and, when necessary, oral antifibrinolytic agents such as tranexamic acid or androgen-based medications, taking side effects into consideration).
- Emergency self-treatment plan: Patients with HAE are advised to have self-administered medication available for use during acute attacks (for example, icatibant or self-injected C1-INH).
- Precautions
- Bradykinin-mediated angioedema does not improve with antihistamines or steroids, creating a risk of misdiagnosis. Distinguishing the cause is important.
- People taking ACE inhibitors should consult a doctor immediately to determine whether to discontinue the medication.
- If episodes recur, allergy and immune testing and evaluation of family history are necessary.
- Complications: Airway obstruction (risk of death), unnecessary surgery due to severe abdominal pain or symptoms resembling intestinal obstruction, and shock (anaphylaxis).
3) Checklist Before an Outpatient Visit (Items to Bring and Example Questions)
- Items to bring
- List of current medications (especially ACE inhibitors, ARBs, NSAIDs, antibiotics, biologic agents, etc.) — including medication names, doses, and dates started
- Previous medical certificates and test results (if possible, including C4 and C1-INH level and functional test results)
- Photos taken when symptoms occur (the swollen area and changes over time)
- Symptom diary (time of attack, duration, triggers, accompanying symptoms, and response to treatment)
- Family history information (if hereditary angioedema is suspected)
- Emergency treatments previously used (whether epinephrine was used and hospital visit records)
- Questions to record in advance for the outpatient visit (having this information ready can make the consultation smoother)
- When the attack started, how long it lasted, and how often it recurs
- Whether difficulty breathing or tongue or throat symptoms occurred
- Recently started medications or food or physical stimuli (cold, heat, etc.)
- Whether anyone in the family has had similar symptoms
If emergency symptoms (difficulty breathing, throat swelling, or reduced consciousness) are present, do not wait for an outpatient appointment; go to the emergency room immediately.
4) Examples of General Questions to Ask the Doctor
- What is causing my symptoms? Is it histamine-mediated or bradykinin-mediated (HAE or drug-induced)?
- What additional tests are needed (blood tests, allergy tests, or C4/C1-INH tests)?
- What are the effects and side effects of the medication you are prescribing now?
- What are the emergency treatment instructions if I develop difficulty breathing (such as self-administered medication or epinephrine use)?
- What should I avoid in my lifestyle to prevent episodes? Do my family members need to be tested?
5) Examples of Disease-Specific Questions
- If hereditary angioedema (HAE) is suspected
- "Can C4 levels and antigenic and functional tests of C1 esterase inhibitor (blood tests) be performed? Depending on the results, what long-term treatment (for example, regular C1-INH replacement or lanadelumab) is recommended?"
- "Can I be prescribed self-administered medication to use at home during an acute attack (for example, icatibant or self-injected C1-INH)? How should it be used and stored?"
- If drug-induced angioedema (for example, ACE inhibitor-induced) is suspected
- "Could the ACE inhibitor I am currently taking be the cause of my angioedema? If I need to stop it, what alternative medications are available?"
- "What is the risk of recurrence after stopping the ACE inhibitor? Which medications should I avoid in the future to prevent a similar reaction?"
Urgent Summary (Things to Remember Immediately)
- If difficulty breathing or swelling of the throat or tongue occurs, go to the emergency room immediately.
- If an allergic cause is suspected: Epinephrine (IM), antihistamines, and steroids are the primary emergency treatments.
- HAE/bradykinin-mediated angioedema does not improve with antihistamines or steroids; C1-INH products and icatibant are effective.