Food Allergy: Causes, Symptoms, Diagnosis, Treatment, and Prevention
Food allergy is a condition where the immune system reacts abnormally to certain foods, leading to symptoms such as itching, swelling, hives, vomiting, diarrhea, wheezing, and anaphylaxis. There are many food allergens that can affect people of all ages, but it is more common in children. Some of the most common food allergens include peanuts, tree nuts, milk, eggs, soy, wheat, fish, and shellfish.
Causes of Food Allergy
A food allergy occurs when the immune system mistakenly identifies some proteins in food as harmful and produces antibodies to combat them. These antibodies, called immunoglobulin E (IgE), trigger the release of chemicals such as histamine, which causes inflammation and allergic symptoms. Some people develop food allergies while others do not, but it may be influenced by genetics and environment.
Symptoms of Food Allergy
The symptoms of food allergy can vary depending on the type and amount of food ingested, the sensitivity of the person, and the organ system involved. Some of the common symptoms are:
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Skin: itching, redness, hives, eczema, swelling of the face, lips, tongue, or throat
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Digestive: nausea, vomiting, abdominal pain, diarrhea, cramps, bloating, gas
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Respiratory: sneezing, runny nose, coughing, wheezing, shortness of breath, chest tightness, asthma
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Cardiovascular: low blood pressure, dizziness, fainting, rapid or irregular heartbeat, shock
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Nervous: headache, tingling, numbness, anxiety, confusion, seizures
A severe and life-threatening allergic reaction called anaphylaxis can cause multiple organ failure and death if not treated right away. When anaphylaxis occurs, it usually occurs within minutes or hours of eating the food, but it can sometimes be delayed for several hours or days. The signs and symptoms of anaphylaxis include:
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Difficulty breathing, swallowing, or speaking
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Swelling of the throat, mouth, or tongue
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Drop in blood pressure, leading to shock
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Loss of consciousness, coma, or cardiac arrest
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Skin rash, itching, or hives all over the body
Diagnosis of Food Allergy
The diagnosis of food allergy is based on the history of the person, the physical examination, and the results of allergy tests. Among the things to consider are the type and amount of food consumed, the duration of the symptoms, the medications taken, and the allergy history of the family members. During a physical examination, you should look for signs of allergic reactions, such as rashes, swelling, or breathing difficulties. Allergy tests can be used to confirm specific food allergens and the degree of sensitivity to them. They include:
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Skin prick test: A small amount of the food extract is placed on the skin and pricked with a needle. If the person is allergic, a red, itchy bump will appear within 15 to 20 minutes.
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Blood test: A sample of blood is taken and measured for the level of IgE antibodies to the food. A high level of IgE indicates an allergy.
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Oral food challenge: The person is given increasing doses of the food under medical supervision and monitored for any reactions. This is the most accurate but also the most risky test, as it can trigger anaphylaxis.
Treatment of Food Allergy
Whenever you have a food allergy, you should avoid the food that causes it. You may need to read food labels carefully, ask about the ingredients in food prepared by others, and carry emergency medication in case you are accidentally exposed to food. Food allergy medications include:
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Antihistamines: These drugs can help relieve mild to moderate symptoms, such as itching, hives, or runny nose. They can be taken before or after eating the food, but they cannot prevent anaphylaxis.
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Using an epinephrine auto-injector, you can reverse anaphylaxis effects, including low blood pressure, swelling, and difficulty breathing. It is injected directly into the thigh muscle. The treatment should be given as soon as possible after the onset of symptoms, and immediate medical attention should be sought.
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Corticosteroids: These drugs can help reduce inflammation and swelling in severe cases of food allergy. They are usually given by mouth or intravenously in a hospital setting.
Prevention of Food Allergy
There is no cure for food allergy, but it can be prevented or reduced by taking some measures, such as:
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As breast milk contains antibodies and nutrients that can strengthen the immune system and gut barrier, breastfeeding for at least six months may prevent food allergies in infants.
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A variety of foods can be introduced to infants at around six months of age, and continued breastfeeding can help prevent food allergies, since it exposes the immune system to a variety of foods and induces tolerance to them. However, some foods, such as peanuts, eggs, and fish, should be introduced with caution and under medical guidance, as they are more likely to cause allergy.
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The prevention of food allergen exposure can be achieved by avoiding cross-contamination. You can do this by cleaning utensils, cutting boards, and dishes thoroughly, using separate containers and utensils for different foods, and checking food labels for allergen warnings.
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The importance of educating oneself and others about food allergies cannot be overstated. In addition to learning about the symptoms and treatment of food allergies, parents, friends, and school staff can be informed about the condition and the emergency plan. Wearing a medical alert bracelet or necklace is another way to do so.
It is a serious and potentially fatal condition that affects millions of people worldwide. By understanding its causes, symptoms, diagnosis, treatment, and prevention, one can live a safer and healthier life.
