Food Allergy Testing

Food allergies affect millions worldwide, posing risks that range from mild discomfort to severe, life-threatening reactions. Diagnosing food allergies accurately is essential for effective management and prevention. This article delves into food allergy testing, the types of tests available, how they work, and what individuals need to know to safeguard their health.

What is a Food Allergy?

A food allergy occurs when the immune system mistakenly identifies certain proteins in food as harmful, triggering a response to “fight off” the allergen. Symptoms of food allergies can include:

• Skin reactions like hives or rashes
• Digestive issues, including vomiting or diarrhea
• Respiratory problems, such as wheezing or shortness of breath
• Anaphylaxis, a severe, potentially fatal reaction that requires immediate medical attention

Common food allergens include milk, eggs, peanuts, tree nuts, fish, shellfish, soy, and wheat, though allergies can develop to a wide range of foods.

Why is Food Allergy Testing Important?

Testing for food allergies provides critical information for diagnosing allergies accurately, allowing individuals to manage their diets and avoid potentially dangerous reactions. Food allergy testing can help:

1. Confirm Allergies: Tests can verify suspected allergies, avoiding unnecessary dietary restrictions and identifying the root causes of symptoms.
2. Guide Treatment Plans: Testing provides insight into the severity of allergies, helping doctors create a tailored treatment and management plan.
3. Prevent Severe Reactions: Knowing specific allergens allows individuals to avoid them, significantly reducing the risk of accidental exposure.
4. Improve Quality of Life: With an accurate diagnosis, individuals can safely navigate their food choices and social situations involving food.

Types of Food Allergy Tests

Multiple testing methods are available for diagnosing food allergies, each with unique benefits and limitations. Here are some of the most common tests:

1. Skin Prick Test (SPT)
   • How it Works: During an SPT, a small amount of a suspected allergen is placed on the skin, which is then lightly pricked or scratched to allow the substance to enter the skin.
   • Results: If a raised bump or “wheal” appears within 15-20 minutes, it indicates a possible allergy to that substance.
   • Pros and Cons: SPTs are quick and relatively accurate, especially for identifying common allergens. However, false positives can occur, and it may not be suitable for individuals with severe skin conditions.
2. Blood Test (Specific IgE Test)
   • How it Works: A blood sample is taken to measure the level of IgE antibodies in response to specific allergens. Higher IgE levels often indicate an allergy.
   • Results: Blood tests are analyzed in a laboratory, with results provided within a few days.
   • Pros and Cons: Blood tests are helpful when skin tests aren’t feasible, such as with individuals with skin conditions or those unable to discontinue antihistamines. However, these tests can be more expensive and may yield false positives.
3. Oral Food Challenge (OFC)
   • How it Works: Under medical supervision, the patient consumes small, gradually increasing amounts of the suspected allergen to monitor for reactions.
   • Results: If symptoms develop, the test confirms an allergy; if not, the food may be safe to consume.
   • Pros and Cons: OFCs are considered the gold standard for diagnosing food allergies, offering high accuracy. However, due to the risk of severe reactions, they must be performed in a controlled medical setting.
4. Elimination Diet
   • How it Works: Individuals eliminate suspected allergens from their diet for a few weeks and then reintroduce them one at a time while monitoring symptoms.
   • Results: If symptoms improve when the allergen is removed and return upon reintroduction, an allergy may be present.
   • Pros and Cons: Elimination diets are a non-invasive, low-cost option, but they are time-consuming and may not pinpoint the exact allergen without further testing.
5. Component-Resolved Diagnostics (CRD)
   • How it Works: CRD is a blood test that measures the body’s response to specific proteins within an allergen, rather than the whole allergen.
   • Results: This method provides a detailed profile, often predicting the severity and cross-reactivity of allergies.
   • Pros and Cons: CRD is valuable for those with multiple allergies or cross-reactive allergens. It is, however, more costly and not as widely available as standard tests.

Who Should Consider Food Allergy Testing?

While food allergy testing is most common for those with severe or unexplained symptoms, it can also benefit:

• Children and Infants: Early testing can help identify allergies that may be outgrown or persist into adulthood.
• Individuals with Family Histories of Allergies: Those with a family history of allergies may be more prone to developing food allergies themselves.
• People with Atopic Conditions: Conditions like asthma, eczema, and allergic rhinitis often coexist with food allergies, making testing beneficial.
• Individuals with Unexplained Symptoms: Testing can provide answers for those experiencing recurring symptoms such as hives, gastrointestinal discomfort, or respiratory issues without a clear cause.

Interpreting Food Allergy Test Results

It’s essential to work with an allergist or healthcare provider when interpreting test results. A positive test does not always mean a severe or life-threatening allergy; it simply indicates sensitization to the allergen. Conversely, a negative result does not rule out all risk. An allergist can provide guidance on managing allergies, avoiding allergens, and determining the appropriate treatment.

Management and Treatment of Food Allergies

Managing food allergies requires a proactive approach that includes:

1. Avoidance of Allergens: Knowing and avoiding specific allergens is the first line of defense in managing food allergies.
2. Reading Labels Carefully: Understanding food labels and ingredient lists is essential to avoid hidden allergens in processed foods.
3. Using Medication for Reactions: Having medications like antihistamines or epinephrine auto-injectors on hand can be lifesaving in case of accidental exposure.
4. Creating Allergy Action Plans: For children, especially in schools or social settings, having an allergy action plan with clear instructions can prevent severe reactions.

Future of Food Allergy Testing

As technology advances, food allergy testing is likely to become more accessible, accurate, and personalized. Innovations may include at-home testing kits, improved testing for cross-reactive allergens, and better predictive tools to help individuals manage allergies proactively.

Conclusion

Food allergy testing is an essential tool for individuals and families managing food allergies. With several testing options available, from skin tests to advanced blood tests, allergists can provide a tailored approach that ensures accuracy and safety. Working with a healthcare provider to determine the most suitable tests and interpret results can make a significant difference in quality of life and peace of mind.

Need a lab for food allergy testing?

Contract Laboratory often receives test requests from companies and organizations needing laboratories to perform food allergen testing or research such as the following:

• ISO-certified laboratory is needed for clarified butter testing for total milk allergens, casein-only allergens, and total lactose content.
• Food Laboratory is needed for food allergen testing for gliadin.
• Bioanalytical laboratory needed for allergen testing. Western Blot testing of eggs using the method of detection of egg (ovalbumin and ovomucoid)by Western blot (egg).
• Europe ISO17025 Product Safety Laboratory required for testing food allergens
• Food analytical chemistry laboratory needed for dairy testing: silver ion thin layer chromatography testing followed by GC/MS testing of a milk sample to quantify total fatty acid content including CLA (C18:2), two major isomers (c9, t11, and c10, t12), and omega fatty acid ratio (6:3).
• Food laboratory needed for milk powder quality testing: Heat Instability: Alcohol Test > 75% IDF: 133:1981 Clot on boiling test Negative K.S.S 150:1982 Objectionable matter Minimal/25g MAF Dairy Division Foreign matter Absent/25g MAF Dairy Division Inhibitory substances 0.005 IU/ml Max MAF Dairy Division Antibiotics Negative MAF Dairy Division
• to view more test requests, click here

If you need a laboratory to help with any of your food or product testing, let us help! Call Contract Laboratory at 1-855-377-6821 or submit a test request on our website!