Angioedema - Types, Causes, Symptoms, Risk Factors, Diagnosis, and Treatment

What Is Angioedema?

Angioedema is swelling in the inner surface of the skin. It is usually harmless and clears within a day, but it becomes life-threatening when the airway gets blocked. Hives sometimes accompany angioedema.

What Are the Symptoms of Angioedema?

• Large, thick, firm swellings.

• Mild pain, redness, and warmth in the affected areas.

• Swellings within minutes to hours, usually around the eyes, lips, or cheeks.

• Its common location includes the face, throat, uvula (the little piece of skin that hangs from the back of your throat), larynx (voice box), arms, hands, legs, or feet. Rare location includes around genitals and intestines.

• It may be seen along with hives.

• Some rare symptoms of angioedema include breathing difficulty, red, irritated eyes, stomach pain, feeling sick, loose stool, dizziness, and fainting.

What Causes Angioedema?

Angioedema is caused by a rapid increase in permeability of capillaries beneath the skin and post-capillary venules with localized fluid discharge. Most cases of angioedema are dependent upon the release of either histamine or bradykinin. The histamines are released by antigen-dependent crosslinking of immunoglobulin E (IgE) at the mast cells or basophils surface, as in typical allergic reactions.

Bradykinin is a chemical mediator of angioedema associated with angiotensin-converting enzyme (ACE) inhibitors that prevent bradykinin destruction. This raises the bradykinin level. The bradykinin forms either by the tissue bradykinin-forming pathways or plasma. C1 inhibitor (INH) deficiency, either be inherited or acquired, led to overproduction of bradykinin caused without inhibition of the enzymes kallikrein and activated factor, XII.

What Are the Types of Angioedema?

What Are the Risk Factors of Angioedema?

Angioedema is seen as widespread. Some risk factors of angioedema include:

• History of angioedema.

• History of any allergic reactions.

• Family history of angioedema.

• History of thyroid disease, lupus, lymphoma, HIV, hepatitis, cytomegalovirus, Epstein-Barr virus, or blood transfusion.

• History of asthma and NSAIDs.

• Intake of angiotensin-converting enzyme inhibitors.

• History of recombinant tissue plasminogen activator (rtPA ) treatment for a stroke.

How Is Angioedema Diagnosed?

Angioedema is usually diagnosed with a complete examination at adequate lighting and a good history of swelling. Sometimes it may require an allergy test or a blood test for confirmation.

• Skin Prick Test – where the skin is pricked with a small amount of the doubted allergen to check for the skin reaction.

• Blood Test - is done when a genetic inheritance is suspected. C1 esterase inhibitor level is tested for immune system response. Low C1 esterase inhibitor level shows decreased immune system response.

How Can Angioedema Be Treated?

Angioedema is usually a self-limiting reaction. Medications are not mandatory but are prescribed to control itching or any discomfort. The drug includes;

• Antihistamine and oral corticosteroids for swelling, inflammation, itching.

• Drugs to suppress the immune system.

• Leukotriene antagonists for pain and swelling.

• Blood protein regulators for hereditary angioedema.

• Epinephrine is given in a severe allergic outbreak (anaphylaxis). When the attack repeats, a pen-like device loaded with epinephrine is carried for emergency auto-injectors. Different types of auto-injectors are available in the market.

• If the airway passage is involved, the priority must be to maintain the airway circulation by intubation or rarely a tracheostomy and administer oxygen.

What Is the Prognosis of Angioedema?

Angioedema usually has a good prognosis. Rarely seen as a life-threatening issue.

What Are the Complications of Angioedema?

Angioedema becomes life-threatening when it involves the tongue or throat and blocks the airway.

What Are the Preventive Measures?

Angioedema can be prevented by taking the following measures;

• Try to avoid the identified triggers.

• Bath and change your clothes when exposed to pollen or animals that have been a trigger in the past.

What Lifestyle Modifications Are Needed?

• Avoiding triggers is the primary treatment.

• Covering the affected area with a cold cloth or rubbing an ice cube on it for a few minutes can help calm the skin and prevent scratching.

• Taking a comfortably cool bath can relieve itching. Some people have benefited from bathing in baking soda or oatmeal powder sprinkled with cold water. But this isn't a solution for long-term control of prolonged itching.

• Wear loose, smooth-textured cotton clothing and avoid wearing rough, tight, scratchy clothes or woolen clothes.

• Sun protection by applying sunscreen generously for about 30 minutes before going outside. When out-of-doors, look for a shady place to help relieve discomfort.

Conclusion

Angioedema is life-threatening with multiple subtypes, each with a distinct disease pattern. Each of these subtypes of angioedema has a specific approach to diagnosis and management. The most effective treatment depends on identifying the cause and the clinician's knowledge and experience with the treatment procedure.