Angioedema

Description

Angioedema is swelling of the deep dermis and subcutaneous tissues. It is usually an acute mastocidal cell-mediated reaction caused by exposure to allergens such as drugs, poisons, foods, pollen, or animal dander.

The condition may also represent an acute reaction to ACE inhibitors; an inherited or acquired disorder of complement activation.

The main symptom is swelling, which can be serious. The diagnosis is made by examination.

Treatment is by limiting swelling in the airways, as well as removing or avoiding the allergen and drugs to reduce swelling, eg H1 blockers.

Oedema, usually localized, is due to increased vascular permeability and extravasation of intravascular fluid.

Known mediators of increased vascular permeability – permeability, are:

• Mast cell cells, obtained from mediators such as histamine, leukotrienes, prostaglandins;
• Bradykinin and mediators obtained in the complement process;

Mast cell cells derived from mediators tend to affect the layers of superficial skin tissue.

In these areas, mediators cause urticaria and pruritus /itching/, thus accompanying mastoid cell-mediated swelling.

However, when subcutaneous swelling is brandykinin-mediated, the dermis is usually spared and urticaria and pruritus do not occur.

In some cases, the mechanism and causes of the condition cannot be established. Several of the possible causes – calcium channel blockers and fibrinolytics have no discovered mechanism.

And sometimes a cause with a known mechanism is clinically overlooked and dismissed.

Angioedema can be acute or chronic – lasting more than 6 weeks. There is also a hereditary form.

What are the symptoms?

The swelling is often asymmetrical and slightly painful. It often affects the face, lips and/or tongue and can also appear on the back, arms, legs or genitals.

Swelling of the upper airways can lead to respiratory distress and wheezing. But stridor can be mistaken for asthmatic.

Also, complete obstruction of the airways may occur. Edema of the intestines can cause nausea, vomiting, colic, abdominal pain and/or diarrhea.

Other manifestations of the condition depend on the mediator:

• Masticidal cell-mediated edema

It develops from a few minutes to a few hours. It may be accompanied by other manifestations of acute allergic reactions, for example itching, urticaria, facial flushing, bronchospasm and anaphylactic shock.

• Bradykinin-mediated edema

It develops from a few hours to a few days. It is not accompanied by other manifestations of allergic reactions.

Treatment of angioedema

• Keeping the airway open;
• When the condition is mastocidal cell-mediated, antihistamines are administered, and sometimes corticosteroids and epinephrine are used;
• When the swelling is associated with an ACE inhibitor, C1 inhibitor concentrate is used;
• In the recurrent idiopathic form, an antihistamine is administered orally;

Ensuring airway patency is of the highest priority. When the condition is mastocidal cell-mediated treatment quickly causes a reduction in airway swelling.

But if the swelling is bradykinin mediated, the swelling decreases more than 30 minutes after the start of the treatment. Therefore, endotracheal intubation is necessary in this condition, and if the airways are affected, epinephrine is used.

Treatment also consists of removing or avoiding the allergen and using medications that relieve symptoms.

If the cause of the condition cannot be found, then it is recommended to stop all types of non-essential drugs that the patient is taking.

In mast cell-mediated swelling of the deep and other subcutaneous tissues, drugs that can relieve symptoms are H1 blockers such as prednisone.