About Food Allergies
A food allergy is an adverse reaction caused by the immune system’s response to a specific food protein. It is important to distinguish food allergies from other non-immune-related reactions, such as food intolerances caused by metabolic issues or reactions to harmful substances in foods. Food allergens are specific components of food, usually proteins, that are recognized by the immune system and trigger an immune reaction. This immune reaction can result in a range of symptoms, from mild to life-threatening.
Food allergies can be classified into two types:
- Immunoglobulin E (IgE)-mediated: The immune system produces antibodies called IgE in response to the allergen, leading to an immediate allergic reaction.
- Non-immunoglobulin E (non IgE)-mediated: This involves other parts of the immune system and typically causes delayed allergic reactions.
The prevalence and severity of food allergies are increasing globally, and there is currently no definitive treatment for food allergies. Management typically involves avoiding the trigger foods and carrying emergency medications for severe reactions.
The root causes of food allergy are complex interactions between genetic and environmental factors in early life.
Non-modifiable risk factors for food allergies cannot be changed or controlled. These include:
- Male sex
- Ethnicity (such as East Asian descent)
Modifiable risk factors for food allergies can be influenced or changed. These include:
- Hygiene: Over-cleaning can limit exposure to germs that help train the immune system, making it more likely to react to harmless food proteins.
- Antibiotic use: Too many antibiotics can upset the balance of helpful bacteria in the gut, which support a healthy immune system.
- Dog exposure: Being around dogs early in life might help lower allergy risks by exposing the immune system to healthy bacteria.
- When and how foods are introduced: Delaying the introduction of certain foods, like peanuts or eggs, may increase the risk of allergies.
- Antacid use: Antacids can change how the stomach breaks down food, leading to immune system reactions to food proteins.
- Low vitamin D levels: Vitamin D supports a healthy immune system, and not getting enough might increase allergy risks.
- Not enough omega-3-fats: Healthy fats found in fish and some plants can help reduce inflammation and support the immune system.
- Low antioxidants in diet: Antioxidants, found in fruits and vegetables, protect the body from inflammation. Too few can weaken the immune system.
- Obesity: Obesity can cause inflammation in the body, which might make food allergies more likely.
It's important to note that while these modifiable risk factors have been identified, further research is needed to determine their precise impact on the development of food allergy. It is always recommended to consult with a healthcare professional for personalized advice and guidance.
The most common early symptoms of a food allergy include:
- Swelling of the tongue, mouth, or face
- Red, itchy bumps on the skin (hives)
- Itching of the lips and mouth
- Wheezing
- Stomach pain
- Nausea, vomiting, or both
- Diarrhea
As the severity of a food allergy progresses or if it reaches a higher stage, additional symptoms may occur. These can include:
- Swelling that blocks the lips, tongue, or throat
- Trouble swallowing
- Shortness of breath or wheezing
- Turning blue
- Drop in blood pressure (feeling faint, confused, weak)
- Loss of consciousness
- Chest pain
- A weak pulse
- Sense of impending doom
It's important to note that not everyone will experience all of these symptoms, and each reaction may vary. If you or someone you know experiences symptoms of a food allergy, it is crucial to seek immediate medical attention. Anaphylaxis, a severe and life-threatening allergic reaction, requires immediate treatment.
To diagnose food allergies, the following examinations, tests, and procedures are commonly performed:
- Detailed history: A doctor will ask about your symptoms and the foods you consumed before the symptoms started.
- Physical examination: This helps rule out other conditions that may be causing the symptoms.
- Skin prick test: A healthcare professional pricks your skin with a needle or plastic device to introduce a small amount of allergen. If you're allergic to that substance, a raised bump will develop.
- Blood test: A sample of your blood is taken and sent to a lab for analysis. This test measures specific IgE antibodies, which indicate an allergic response.
To assess the severity of food allergies, additional examinations, tests, and procedures may be performed:
- Basophil Activation Test (BAT): This test measures how certain white blood cells (called basophils) react when exposed to allergens. It can help predict the likelihood of a severe allergic reaction.
- Double-Blind, Placebo-Controlled Food Challenge (DBPCFC): This is considered the most accurate test for diagnosing food allergies. During the test, a person consumes small amounts of a suspected allergen and a placebo under medical supervision to check for allergic reactions.
Remember, proper diagnosis and evaluation should be conducted by a healthcare professional. They will determine which tests are necessary based on your specific situation.
The goals of food allergy treatment include reducing allergic reactions (desensitization), helping the body tolerate certain foods (induction of tolerance), maintaining this tolerance over time (sustained unresponsiveness), and possibly achieving long-term remission where allergic reactions no longer occur. Here are some recommended treatments and how they work to achieve these goals:
- Allergen-specific immunotherapy (AIT): AIT involves gradually exposing a person to increasing amounts of the allergenic food. The goal is to make the body less sensitive to the food, reducing the chance of an allergic reaction if accidentally exposed. Over time, AIT may help the person tolerate normal servings of the food without any symptoms.
- Avoidance diet: The primary treatment is avoiding the foods that cause reactions. This long-term approach helps prevent accidental exposure and lowers the risk of severe allergic reactions.
- Health behavior changes: Making certain lifestyle changes can help manage food allergies effectively. These may include reading food labels carefully, avoiding cross-contamination, carrying emergency medication (such as epinephrine), and educating others about the allergy.
- Experimental therapies: New treatments, such as food AIT and other experimental therapies, are being studied to help people with food allergies develop permanent immune tolerance. However, more research is needed before these therapies can become widely implemented.
It's important to note that specific medication types and therapies may vary depending on individual circumstances. Always consult with a healthcare professional for personalized advice.
Medication dosing may be affected by many factors. Check with your health care professional about dosing for your individual situation. Other side effects can occur. Check with your health care professional or read the information provided with your medication for additional side effect information.