Anaphylaxis: what it is, symptoms, causes and treatment

Anaphylaxis is a severe acute allergic reaction that begins immediately or within a few hours, after contact with an allergenic substance, such as food, medicine, insect venom or material, causing symptoms such as difficulty breathing, a feeling of a closed throat, swelling in the mouth, tongue or face, blistering of the skin or hives.

Anaphylaxis, also known as anaphylactic shock, is caused by an exaggerated reaction of the immune system, upon contact with the allergenic substance, quickly producing antibodies and substances, such as histamine, leukotrienes and prostaglandins, resulting in symptoms, which can be fatal if not treated. treated quickly.

In case of suspected anaphylaxis, medical attention should be sought immediately or the nearest emergency room so that treatment can be carried out as quickly as possible, and generally includes the application of adrenaline, corticosteroids and injectable antihistamines, intravenous serum , bronchodilators and monitoring of vital signs.

Symptoms of anaphylaxis

The main symptoms of anaphylaxis are:

• Swelling of the lips, tongue and/ eyes;
• Itching and redness of the skin;
• Swelling of the throat, with the feeling of a lump in the throat, as if it were closed;
• Itchy throat;
• Difficulty breathing and feeling short of breath;
• Breathing is more labored, and wheezing may be noted when breathing;
• Change in heartbeat and decrease in pressure;
• Pallor;
• Dizziness or fainting.

The symptoms of anaphylaxis begin immediately after contact with the allergenic substance, progressing quickly, generally within an hour, and this first hour is essential for treatment, as most cases of fatality occur during this period, if there is no quick medical care.

Therefore, when symptoms of anaphylaxis or anaphylactic shock appear, you should seek medical attention immediately, the nearest emergency room or call SAMU, so that treatment can be carried out as quickly as possible. See what first aid should be like for a person in anaphylactic shock.

How to confirm the diagnosis

The diagnosis of anaphylaxis is made in the hospital by the general practitioner through assessment of symptoms and contact with allergenic substances, and laboratory tests are not necessary to confirm the diagnosis. Therefore, the doctor must start treatment immediately to avoid complications.

Possible causes

Anaphylaxis is caused by an exaggerated reaction of the immune system when coming into contact with an allergenic substance, causing the body to produce antibodies, such as immunoglobulin Ig-E, in addition to other substances, such as histamine, prostaglandins, leukotrienes, tryptase, factors platelet activation and tumor necrosis factor (TNF-alpha), resulting in symptoms.

Some allergenic substances that can lead to the development of anaphylaxis are:

• Foods such as egg, milk, soy, gluten, wheat, peanuts, tree nuts and other tree nuts, fish, shrimp, shellfish, crustaceans and Kiwi;
• Medications, most commonly antibiotics, dipyrone, acetylsalicylic acid, anti-inflammatories, anesthetics or vaccines;
• Insect poison, such as bees, ants, wasps or wasps;
• Materials such as latex or synthetic fabrics;
• Metals, such as nickel, cobalt, chromium or silver;
• Mite, mold, pollen, animal hair or saliva;
• Paints or enamels;
• Medicinal products, such as iodine or mercury;
• Radiological contrasts, such as iodine or gadolinium;
• Cosmetic products, such as perfumes, creams, soaps or shampoo;
• Plants, such as nettle or poison ivy;
• Temperature variations, as in the case of cold allergy.

Furthermore, although it is rare, anaphylaxis can occur when physical exercise, such as running, walking or cycling, or any other type of sport, is performed within the first two hours after eating certain foods, such as omega 5 present in wheat, for example. , known as exercise-induced anaphylaxis.

Know how to identify what could be causing the allergy through an exam.

How the treatment is carried out

The treatment of anaphylaxis should be started as soon as possible in the hospital with the administration of injectable adrenaline directly into the muscle and clearing the airways. If necessary, the doctor may repeat intramuscular adrenaline every 5 minutes for a maximum of 3 administrations.

In addition, other medications can be administered, such as antihistamines, such as diphenhydramine, cimetidine or ranitidine intramuscularly or intravenously, and corticosteroids, such as methylprednisolone or hydrocortisone, directly into the vein.

For hypotension, saline or a crystalloid solution can be administered directly into the vein. After that, the person remains under observation in the hospital, where their vital signs are monitored.

Other medications that can be used after the person is stabilized are corticosteroids, such as methylprednisolone or prednisolone, inhaled bronchodilators, such as salbutamol, for example.

If a person is at risk of having severe allergic reactions, the doctor may prescribe an adrenaline injection for the person to always have with them, and to use in emergency cases, until they are treated at the hospital. Learn how to use the adrenaline injection.