Published: 18 Jun 2025

ICD9: 995.1      ICD10: T78.3XXA      ICD11: 4A00.14

Angioedema is a type of swelling that affects deeper layers of the skin, typically the dermis, subcutaneous tissue, mucosa, and submucosal tissues.
It's similar to hives (urticaria) but occurs in deeper layers, leading to more pronounced swelling.

Here's a breakdown of what you need to know about angioedema:

Key Characteristics:

Swelling: The primary symptom is swelling, which can be dramatic and uncomfortable. It often affects:
Face: Lips, tongue, eyelids, cheeks
Throat: This is the most dangerous location, as it can obstruct breathing.
Extremities: Hands, feet, genitals
Abdomen: This can cause abdominal pain, nausea, vomiting, and diarrhea.

Location: Unlike hives, which are superficial and itchy, angioedema affects deeper tissues.

Duration: Swelling usually develops within minutes to hours and can last for 24-72 hours (or longer in some cases).

Pain/Discomfort: It's often painless, but can be accompanied by a burning or tingling sensation. Throat swelling can cause hoarseness or difficulty swallowing. Abdominal involvement can cause significant pain.

Causes:

Angioedema can be caused by various factors:

Allergic Reactions: This is the most common cause. Common allergens include:
Foods (e.g., peanuts, shellfish, nuts, eggs, milk)
Insect stings (e.g., bee, wasp)
Medications (e.g., penicillin, NSAIDs)
Latex

Medications:
ACE inhibitors: These blood pressure medications are a common cause of angioedema, and it can develop months or even years after starting the medication.
NSAIDs: (e.g., ibuprofen, naproxen)
Other medications: Antibiotics, aspirin, certain chemotherapy drugs.

Hereditary Angioedema (HAE): This is a rare genetic condition caused by a deficiency or malfunction of a protein called C1 esterase inhibitor. It leads to unpredictable episodes of angioedema, often without hives.

Acquired Angioedema: This is also rare and is caused by an autoimmune condition or certain cancers that affect the C1 esterase inhibitor.

Idiopathic Angioedema: In some cases, the cause of angioedema cannot be identified.

Symptoms:

Swelling: As mentioned above, swelling is the defining symptom.
Difficulty breathing: This is a medical emergency, especially if the throat is affected.
Hoarseness: Can indicate swelling in the larynx (voice box).
Difficulty swallowing: Also a sign of throat swelling.
Abdominal pain, nausea, vomiting, diarrhea: If the angioedema affects the intestines.
Hives (urticaria): May be present, especially in allergic reactions, but are not always present.

Diagnosis:

Medical History: The doctor will ask about your symptoms, medications, allergies, and family history.
Physical Exam: The doctor will examine the areas of swelling.
Blood Tests:
C1 esterase inhibitor levels: To check for hereditary or acquired angioedema.
Allergy testing: To identify potential allergens (skin prick tests or blood tests).

Treatment:

Treatment depends on the severity of the angioedema and the underlying cause:

Emergency Treatment (for severe cases, especially with breathing difficulties):
Epinephrine (EpiPen): Used for severe allergic reactions.
Antihistamines: Like diphenhydramine (Benadryl).
Corticosteroids: Like prednisone.
Oxygen: To help with breathing.
C1 esterase inhibitor concentrate: For hereditary angioedema.
Icatibant and Ecallantide: Other medications used to treat hereditary angioedema attacks.
In severe cases, intubation (placing a breathing tube) or a tracheostomy (creating an opening in the trachea) may be necessary.

Treatment for Mild Cases:
Antihistamines: To reduce swelling and itching.
Corticosteroids: To reduce inflammation.
Avoiding triggers: If the cause is known (e.g., avoiding certain foods or medications).

Long-Term Management (for Hereditary Angioedema):
C1 esterase inhibitor concentrate: For prevention and treatment of attacks.
Lanadelumab: A monoclonal antibody that helps prevent attacks.
Berotralstat: An oral medication that helps prevent attacks.

When to Seek Medical Attention:

Any difficulty breathing or swallowing is a medical emergency. Call 911 or your local emergency number immediately.
Significant swelling of the face, lips, tongue, or throat.
Severe abdominal pain.
If you have a known history of angioedema and are experiencing symptoms.
If you are concerned about your symptoms.

Important Considerations:

Carry an EpiPen: If you have a history of severe allergic reactions, your doctor may prescribe an epinephrine auto-injector (EpiPen) for emergency use. Learn how to use it properly and carry it with you at all times.
Wear a medical alert bracelet: If you have hereditary angioedema or other conditions that cause angioedema, consider wearing a medical alert bracelet or necklace to inform medical personnel about your condition in case of an emergency.
Inform your doctors and dentists: Tell all your healthcare providers about your history of angioedema, especially before any medical procedures or surgeries.
Avoid triggers: If you know what triggers your angioedema, avoid those triggers whenever possible.

In summary, angioedema is a serious condition that can be life-threatening if it affects the airway. Prompt diagnosis and treatment are essential. If you suspect you have angioedema, see a doctor as soon as possible.