What is angioedema?
Angioedema is an irritation that causes inflammation of the skin similar to hives. Unlike the latter, which only affects the superficial tissues of the skin, angioedema affects the deep subcutaneous layers.
The skin, mucous membranes and submucosal tissues are swollen, but there are no hives, as in urticaria. Although angioedema may not cause itching, it is more severe than urticaria. The two conditions often coexist and overlap. The swelling of the skin usually lasts from 24 to 72 hours.
Prognosis of the disease
Angioedema is generally harmless and its symptoms leave no lasting signs.
If the area subject to the reaction is the throat, there is a danger that the throat may become obstructed, causing breathing and swallowing problems and, consequently, a risk of suffocation.
Angioedema is a skin irritation.
Symptoms of angioedema
The most common symptoms are as follows:
- Swelling of specific areas, such as around the eyes, tongue, lips, genitals, throat;
- Usually no skin rash (as opposed to hives);
- Burning sensation, numbness, itching, pain, and warmth in the affected areas;
- Pain in the abdomen if the mucosa of the gastrointestinal tract is inflamed;
- Difficulty urinating (if angioedema affects the bladder or urethra).
Diagnosis of angioedema
The clinical immunologist is often able to diagnose angioedema through objective testing and after collecting the patient’s medical history.
There are also other tests that can aid in the diagnosis of this disorder, such as a blood draw and skin prick test, which are used to detect allergic angioedema and hereditary angioedema. Idiopathic angioedema, on the other hand, is detected by diagnosis of exclusion, i.e. excluding other similar pathologies until angioedema can be confirmed.
What are the causes of angioedema?
There are several possible causes of angioedema, depending on its nature:
- allergic angioedema: this can be caused by allergy to certain foods (such as crustaceans, dairy products, eggs and nuts), food additives (such as sodium glutamate), certain medications, latex, wasp and bee stings, or stings from snakes and jellyfish;
- non-allergic drug-induced reaction;
- Idiopathic angioedema: In most cases it is not possible to find a specific cause for the angioedema; in this case we speak of idiopathic angioedema. Some risk factors for the development of the latter have been identified (infections, alcohol and caffeine consumption, consumption of spicy foods, living in places with extreme temperatures, wearing tight clothing, stress); in addition, a good percentage of idiopathic angioedema cases may be related to systemic lupus erythematosus or other autoimmune diseases;
- congenital angioedema: this is genetically transmitted and is due to C1 inhibitor deficiency;
- acquired angioedema: C1-INH inhibitor deficiency can be acquired during life, for example in people with lymphoma and other autoimmune diseases.
Can it be prevented?
Idiopathic angioedema could be prevented by abandoning the following habits:
- caffeine and alcohol consumption;
- consumption of spicy foods;
- wearing tight clothing;
- stress;
- undergoing temperature extremes (e.g., very hot showers or baths, air conditioning, etc.).
Treatments for angioedema
If angioedema causes breathing difficulties, unblocking the airway (e.g. by intubation) is a priority.
On the other hand, if the symptom does not represent a danger to breathing, the symptoms usually disappear within a few hours or two to three days at the most.
Some tips to reduce swelling are:
- cold compresses on the affected area;
- take a cold (but not freezing) shower;
- do not wear tight clothing;
- do not rub the affected area;
- take antihistamines or corticosteroids;
- In severe cases it may be advisable to give an adrenaline injection.
Which specialist to contact?
An expert in clinical immunology will guide the patient through the most appropriate diagnostic and therapeutic procedure to treat angioedema.