Food allergies occur when your immune system mistakenly identifies certain foods as harmful, leading to reactions that can vary from mild to severe. These reactions can impact different areas of the body, including severe cases like anaphylaxis, a potentially life-threatening condition that requires immediate medical attention.
Identifying a Food Allergy Food allergy symptoms vary in severity:
Immediate Symptoms: This may occur within minutes to two hours after ingestion.
Delayed Reactions: Rarely, symptoms may appear 4-6 hours later, particularly with conditions like eczema or rare red meat allergies from lone star ticks.
The most severe reaction is anaphylaxis, a life-threatening condition requiring immediate treatment with epinephrine (adrenaline). Symptoms of a food allergy can appear immediately after consumption or even days later. Common indicators include:
- Dizziness or lightheadedness
- Itchy skin or hives
- Swelling of the lips, face, or eyes
- Coughing, wheezing, difficulty breathing, or hoarseness
- Sneezing, itchy, runny, or blocked nose
- Nausea or vomiting
- Abdominal pain
- Diarrhea
Allergic reactions can affect multiple systems:
- Skin: Hives, rash
- Gastrointestinal: Vomiting, stomach cramps
- Respiratory: Shortness of breath, wheezing
- Cardiovascular: Shock, weak pulse, pale or blue skin, dizziness
- Other reactions include Oral Allergy Syndrome, causing itching in the mouth and throat from raw fruits or vegetables.
Distinguishing Food Allergies from Food Intolerance
It’s important to differentiate between food allergies and food intolerances:
Food Intolerance: Typically causes bloating and stomach discomfort hours after eating.
Food Allergy: This may result in immediate and potentially severe reactions.
Seek immediate medical help by calling 999 if you experience severe swelling in the mouth or throat, trouble breathing, throat constriction, significant skin color changes, extreme disorientation, or unresponsiveness. Use your adrenaline auto-injector immediately if prescribed, and call 999 even if symptoms improve.
Non-Urgent Advice
If you suspect a food allergy, consult your GP for a thorough evaluation.
Causes of Food Allergies
Food allergies occur when the immune system overreacts to specific foods. In the UK, the 14 major allergens include:
- Celery: Found in soups, sauces, and salads.
- Cereals containing gluten: Includes wheat, barley, and rye.
- Crustaceans: Such as prawns, crab, and lobster.
- Eggs: Present in baked goods and processed foods.
- Fish: Includes species like salmon and cod.
- Lupin: A legume found in some flours and baked goods.
- Milk: Includes dairy products like cheese and yogurt.
- Molluscs: Includes squid, octopus, and clams.
- Mustard: Common in condiments and sauces.
- Nuts: Includes tree nuts like almonds and walnuts.
- Peanuts: Present in snacks and sauces.
- Sesame seeds: Used in bakery products and as toppings.
- Soybeans: Found in products like tofu and soy milk.
- Sulphur dioxide and sulphites: Used as preservatives in dried fruits and some wines.
Oral Allergy Syndrome
This condition causes itching in the mouth and throat after consuming raw fruits or vegetables and is generally mild. Cooking the produce often alleviates symptoms.
Testing for Food Allergies
If a food allergy is suspected, your GP might recommend:
- Skin-prick tests
- Blood tests
- Elimination diet to identify trigger foods
- Maintaining a food and symptom diary can also be beneficial.
Treatment and Management
To manage a food allergy:
- Avoid allergenic foods and check ingredient labels.
- Use antihistamines for mild reactions.
- Carry adrenaline auto-injectors for emergencies.
- Follow an allergy management plan from a specialist.
- Immunotherapy may be an option for children with peanut allergies but should not replace avoidance.
Managing Your Allergy
To effectively manage your food allergy:
Do:
Read food labels and restaurant menus carefully.
Inform friends, family, and institutions about your allergy.
Carry 2 adrenaline auto-injectors.
Notify restaurant and airline staff about your allergy.
Clean surfaces in public places before eating.
Don’t:
Consume foods without verifying their ingredients.
Remove foods from your diet without consulting your GP.
Signs of Allergies
Food allergies occur when the immune system overreacts to specific foods, treating them as harmful and triggering a protective response.
Genetic Factors and Predictability
Family history can influence the likelihood of developing food allergies. Siblings of children with peanut allergies may also be at increased risk.
Triggers and Management
Food Allergy Triggers:
In Children: Milk, eggs, peanuts
In Adults: Fruit and vegetable pollen (oral allergy syndrome), peanuts, tree nuts, fish, shellfish
Avoidance Strategies:
Reading Labels: Ensure allergens are clearly listed.
Eating Out: Inform staff about your allergies and use a “chef card” if available.
Anaphylaxis Treatment
Immediate Action:
Epinephrine: The primary treatment for anaphylaxis. Always carry an auto-injector, check its expiration, and administer it immediately if severe symptoms occur. Seek emergency care right away.
Food Allergy Testing
Diagnostic Tests: Include skin-prick tests, blood tests for IgE antibodies, and oral food challenges to identify specific allergens.
Management and Treatment
Avoidance: The primary strategy involves avoiding the allergenic food, checking labels, and being aware of alternative names for allergens.
Food Allergy in Children
School Emergency Plans: Ensure your child’s school has a plan for managing food allergies, including access to epinephrine.
FAQs
What are the 14 major allergens in the UK? The allergens are celery, cereals containing gluten, crustaceans, eggs, fish, lupin, milk, molluscs, mustard, nuts, peanuts, sesame seeds, soybeans, and sulphur dioxide and sulphites.
Can food allergies be prevented? Early introduction of allergenic foods, like peanuts, might reduce the risk. Consult the latest guidelines from NICE.
Are there treatments for food allergies? Avoiding the allergen is the main treatment. No treatment replaces epinephrine for severe reactions.
Do food allergens remain on objects? Yes, allergens can persist on surfaces and cause reactions if touched or ingested.
Can food allergies develop in adulthood? Yes, they can develop at any age, though they often start in childhood.
Can you outgrow food allergies? Allergies to milk, eggs, wheat, and soy may be outgrown; peanuts, tree nuts, fish, and shellfish are usually lifelong.
What are the chances of having a severe reaction to airborne allergens? Severe reactions to airborne allergens are rare but possible, especially in those with strong food allergies.
How much does food allergy testing cost? Costs vary based on tests and provider. Consult an allergist for detailed pricing.
What is gluten? How common is gluten allergy? Gluten is a protein in wheat, barley, and rye. Gluten allergy, or celiac disease, is an autoimmune disorder triggered by gluten.
For more information or to find an allergist, visit the British Society for Allergy and Clinical Immunology (BSACI).
