What is Anaphylaxis?
Anaphylaxis is a serious, life-threatening allergic reaction. It is mostly caused by our immune system reacting excessively to the allergen (the agent that causes the allergy) when we come into contact with it. Through mechanisms mediated by the immune system, histamine and certain substances are released from mast cells and basophils, causing anaphylaxis. Mast cells are cells found in the connective tissue of many different organ systems, such as the skin or respiratory system, forming a natural barrier against external antigens.
Anaphylaxis begins suddenly and progresses rapidly, and can sometimes be fatal. It often appears within minutes, rarely hours, after contact with the allergen. The prevalence of anaphylaxis in the population ranges from 5 to 200 cases per 10,000 people. Anaphylaxis is an unpredictable condition. Although it is most commonly seen when a person comes into contact with an agent known to cause their allergy, sometimes the first allergic reaction in patients can be anaphylaxis. Some people are more prone to anaphylaxis. The risk is higher for people with allergies, asthma, a history of anaphylaxis, or a family history of anaphylaxis.
What are the Causes of Anaphylaxis?
Anaphylaxis can occur when we come into contact with allergens, but it can also occur during exercise. The main factors that cause anaphylaxis can be listed as follows:
- Allergenic foods (cow's milk, eggs, nuts, fish, some tropical fruits, shellfish and shell-free seafood, etc.)
- Medications (antibiotics, painkillers, certain vitamin medications, contrast agents used during medical imaging procedures such as angiography and tomography, etc.)
- Insect stings (various types of bees, etc.)
- Various medical supplies containing latex.
Anaphylaxis in children is usually caused by food, while in adults it is mostly caused by medications and insect stings.
Sometimes the cause of anaphylaxis cannot be identified. In some cases, physical activity can also cause anaphylaxis in addition to the above factors. In some cases, hormonal effects, infections, and stress can facilitate the development of anaphylaxis.
What are the Symptoms of Anaphylaxis?
After exposure to the responsible allergen, the reaction can develop very quickly within minutes. In some cases, the clinical symptoms of anaphylaxis may appear later, even hours after exposure. The symptoms and findings are listed below according to the systems:
- Skin (most common): Itching, redness, hives (urticaria), angioedema (swelling of the face, lips, eyelids, and any part of the skin).
- Eye: Itching, watering, redness, swelling around the eye.
- Nose and throat: Sneezing, runny nose, nasal congestion, swelling of the tongue.
- Respiratory system: Difficulty breathing, repeated coughing, tightness in the chest, rapid breathing and wheezing/rattling, swelling and itching in the throat, voice changes, feeling of suffocation, inability to swallow.
- Heart and circulatory system: Dizziness, weakness, fatigue, changes in pulse rate, drop in blood pressure.
- Digestive system: Nausea, repeated vomiting, abdominal pain, diarrhea.
- Nervous system: Anxiety, feeling unwell, altered consciousness, fainting.
- Infants: Sudden behavioral changes (irritability—excessive reaction to minor stimuli—inconsolable crying, clinging to parents, drowsiness), persistent vomiting, tachycardia (increased heart rate).
To diagnose an allergic reaction as anaphylaxis, symptoms affecting at least two of the systems listed above must be present.
How is Anaphylaxis Diagnosed?
The diagnosis of anaphylaxis is based on symptoms (as described above) that appear following a possible trigger such as food, medication intake, or a bee sting. However, sometimes conditions such as asthma attacks, fainting, panic attacks, or food poisoning can mimic anaphylaxis. The diagnosis is made after a detailed evaluation of the patient by a pediatric or adult allergist and the appropriate tests are performed.
How is Anaphylaxis Treatment Performed?
- Since the reaction has developed and the patient is at risk of death, the first medication to be administered as soon as possible is adrenaline. Adrenaline should be injected into the muscle in the thigh area. To avoid wasting time, it can be administered by the patient themselves or their relatives without having to go to a healthcare facility. For this purpose, special adrenaline autoinjectors are available. After an adrenaline injection, you should seek immediate medical attention.
- If anaphylaxis develops after an injection of a medication, administration of the medication should be stopped immediately.
- If the patient has low blood pressure, they should be laid on their back with their feet elevated until they reach a healthcare facility to ensure blood circulation.
- After administering adrenaline at the healthcare facility, intravenous fluid administration, antihistamines, and cortisone may be administered; if shortness of breath, cyanosis, or wheezing develops, oxygen and bronchodilator medications may be administered. Due to the possibility of the reaction recurring within the first 24 hours, these patients must be kept under observation in the hospital for 24 hours.
- To prevent patients from experiencing anaphylaxis, allergens should be avoided. After anaphylaxis, suspected triggers encountered on the same day (such as medication, food, insect bites) and the route of exposure to these triggers (oral, intravenous, inhalation, skin contact) should be noted. Allergens that cause anaphylaxis should be identified by an allergist and immunologist. Patients should also avoid these allergens.
- Immunotherapy (allergy shots) is a treatment method for anaphylaxis caused by bee allergies.
- Individuals with a history of anaphylaxis due to bee stings, food, medication, or an unknown cause are advised to carry a card or bracelet indicating that they are anaphylaxis patients. Additionally, it is crucial for patients to carry an epinephrine auto-injector, which is vital and life-saving in the initial treatment, and both they and their loved ones must be trained on how to use this medication.