It is easy to confuse different types of food reactions. For example, gluten and lactose intolerance are common. Intolerance is a different type of reaction that does not involve the immune system.
Causes of Food Allergy
Food allergy is a complex health condition where the immune system reacts negatively to specific substances in food. Although the exact causes are not fully understood, the following factors play a central role:
- Genetic predisposition: There is a clear genetic component. If there are allergies in the family, there is a higher risk of developing a food allergy, as specific genes influence how the immune system reacts.
- Environmental factors: Exposure to various allergens and environmental factors affects the risk. For instance, the timing of when a person first comes into contact with substances like nuts or eggs can play a role.
- Development of the immune system: Since an infant's immune system is not fully developed, it may react differently to new substances, which can lead to allergies being established early in childhood.
- Specific substance exposure: Certain proteins are more allergenic than others. Common examples are proteins in milk, egg whites, and peanuts, which the body may identify as harmful.
- Gut health and microbiome: The balance of the gut flora (microbiome) is crucial. A healthy gut environment can help regulate the immune system and thereby prevent allergic reactions.
Symptoms of Food Allergy:
- Skin reactions: This can include itching, redness, rashes (eczema or hives), swelling, or difficulty scratching. Skin reactions are common in food allergies and can be localized to one area or spread across the body.
- Gastrointestinal symptoms: Food allergy can lead to digestive issues such as nausea, vomiting, abdominal pain, gas, and diarrhea. Stomach and intestinal problems are common, especially in children with food allergies.
- Breathing difficulties: An allergic reaction to food can also affect the airways. Symptoms may include coughing, wheezing, shortness of breath, or tightness in the throat and chest. This is a serious sign and can indicate a potential anaphylactic reaction, which is an emergency.
- Nasal symptoms: A runny nose, nasal congestion, and sneezing can occur, especially if there is a cross-reaction with pollen allergy.
- Circulatory problems: During severe allergic reactions, blood pressure can drop, and the person may experience dizziness, loss of consciousness, or collapse.
- Anaphylactic shock: In very rare cases, food allergy can lead to life-threatening anaphylactic shock. This is an acute reaction that can cause breathing difficulties, rapid heart rate, swelling of the face and throat, and unconsciousness. Anaphylaxis requires immediate medical attention.
Treatment of Food Allergy:
The primary treatment for food allergy is to prevent reactions by strictly avoiding the foods you are allergic to. For severe food allergies, doctors may prescribe allergy medications.
Diagnosis – How does it work?
Confirming a food allergy requires a thorough medical investigation. A single test is rarely enough; the doctor often combines your medical history (anamnesis) with one or more of the following tools:
- Skin prick test: A drop of the suspected food substance is placed on the forearm, and the skin is lightly pricked so the substance can penetrate. If the skin becomes red and swollen (similar to a mosquito bite) within 15 minutes, it suggests an allergic reaction.
- Blood test (IgE antibodies): A standard blood test measures the levels of specific IgE antibodies against various foods. An elevated level indicates that the immune system has developed a defense against the substance, but this must always be interpreted alongside your actual symptoms.
- Elimination and challenge: This is the "gold standard" of allergy investigations. For a period, the suspected food is completely excluded (elimination) to see if symptoms disappear. Afterwards, under strict medical supervision, a small amount of the food is reintroduced (oral food challenge) to see if the reaction returns.
Important: Never perform a food challenge at home on your own if there is a risk of a severe reaction.
Living with Food Allergy in Daily Life
A food allergy requires planning, but with the right routines, you can live a safe and active life. Here are the most important strategies for managing daily life:
- Always read the ingredient list: Ingredients can change in products you have bought before. Learn to recognize hidden names for your allergens (for example, that casein is a milk protein). By law, the 14 most common allergens must always be clearly labeled (often in bold) in the ingredient list.
- Communicate at restaurants: Be clear and specific when eating out. Don't just say "I can't have nuts," but explain that it is an allergy so the kitchen can avoid cross-contamination via cutting boards or utensils.
- Always carry emergency medication: If you have been prescribed an epinephrine auto-injector (e.g., EpiPen or Jext), it should be your constant companion. Ensure both you and those close to you know how to use it. Also, check the expiration date regularly.
- Inform your surroundings: Tell friends, colleagues, and schools/preschools about your allergy. The more people who know how to act during an eventual reaction, the safer your environment will be.