•Sudden, deep swelling of the lips, eyelids, face, or tongue
•Swelling of the hands, feet, or genitals
•Tight, painful, or burning sensation in the swollen area (unlike the itch of hives)
•Hoarse voice or difficulty swallowing when the throat is involved
•Difficulty breathing if the airway is compromised
•Abdominal cramping, nausea, or vomiting (in hereditary angioedema)
•Accompanying urticaria (wheals) in allergic forms
•Episodes resolving spontaneously within 24–72 hours
Causes & Triggers
Angioedema results from increased vascular permeability and fluid leakage into deep dermal and subcutaneous tissues. Allergic angioedema is triggered by foods (nuts, shellfish, eggs, mangoes, certain food dyes), medications (penicillin, NSAIDs, contrast dyes), insect stings, and latex. A critical and under-recognised cause in Indian patients is ACE-inhibitor medications (ramipril, enalapril, lisinopril) widely prescribed for hypertension and heart disease - ACE-inhibitor-induced angioedema can begin days to years after starting the drug. Hereditary angioedema (HAE), caused by C1-inhibitor deficiency, is rare but important and is often misdiagnosed for years in India.
How We Test
Acute allergic angioedema is diagnosed clinically; the priority is airway management. For work-up, specific IgE testing and skin-prick tests identify allergen triggers. A full complement panel including C3, C4, and C1-esterase inhibitor (C1-INH) level and function is essential to diagnose or exclude hereditary angioedema - C4 is typically low during and between attacks in HAE. ACE-inhibitor use should always be reviewed in the medication history. Tryptase level taken within 4 hours of an acute episode confirms mast cell activation.
For acute allergic angioedema, treatment is immediate: intramuscular adrenaline (epinephrine) if the airway is threatened, followed by IV antihistamines and corticosteroids. Patients with a history of severe episodes must carry a self-injectable adrenaline auto-injector (EpiPen). For chronic idiopathic angioedema with urticaria, daily antihistamines and omalizumab provide effective long-term control. Hereditary angioedema requires specialist management with on-demand treatments (icatibant or C1-INH concentrate) and long-term prophylaxis. All patients on ACE inhibitors with angioedema should be switched to an angiotensin receptor blocker (ARB).
Go to an emergency department immediately if swelling involves the throat, causes voice changes, or makes breathing difficult; for recurrent or facial swelling without a clear cause, see an allergy specialist promptly.
Frequently Asked Questions
It can be life-threatening when it involves the throat or airway, causing suffocation. Angioedema of the lips and eyelids alone is rarely dangerous but requires evaluation. Any episode causing voice change, difficulty swallowing, or breathing difficulty is a medical emergency - call 112 or go to a hospital immediately.
Yes - ACE inhibitors such as ramipril, enalapril, and lisinopril, very commonly prescribed in India, can cause angioedema in approximately 0.1–0.7% of users. The swelling typically affects the face and throat and can develop months to years after starting the medication. Your doctor can safely switch you to an alternative blood pressure medication.
HAE is a rare genetic condition caused by a deficiency of C1-esterase inhibitor protein. Unlike allergic angioedema, HAE swelling is not itchy, does not respond to antihistamines or steroids, and can involve the intestines (causing severe abdominal pain). It is diagnosed by a blood complement test (low C4, low C1-INH). Specific treatments are available and early diagnosis is critical.
If your angioedema has been triggered by a known allergen and involved throat swelling or was accompanied by anaphylaxis, then yes - an adrenaline auto-injector (EpiPen) is essential and potentially life-saving. Your allergist will train you and a family member in its use. For non-allergic or hereditary angioedema, different emergency medications are prescribed.
A thorough allergy consultation - including detailed history, complement blood tests, specific IgE testing, and medication review - usually clarifies the likely cause within 1–2 visits. The most important first step is always to rule out ACE-inhibitor use and hereditary angioedema, both of which are diagnosable with specific tests.
