What is Intolerance/Allergy Testing?
Intoleranance testing is a diagnostic method to identify substances that may cause adverse reactions in the body, typically involving food or environmental factors. Unlike allergies, intolerances do not involve the immune system and are generally less severe, often causing symptoms related to digestion, skin or general wellbeing.
Difference between Allergy and Intolerance:
Allergy:
- Immune system reaction, often immediate and can be life-threatening (e.g anaphylaxis)
- Diagnosed with Allergy Testing
Intolerance:
- Difficulty digesting or processing certain substances, usually non-immune related
- Symptoms are often delayed and less severed but can still impact quality of life
Types of Intolerance Testing:
Hydrogen Breath Tests:
- Used to diagnose lactose or fructose intolerance
- Measures hydrogen levels in the breath after consuming a test substance as undigested sugars ferment in the gut and release hydrogen
Blood Tests:
- Measures IgG antibodies to certain foods (different from IgE antibodies related to allergies)
Skin Patch Tests (for non-food intolerances)
- Identifies reactions to environmental substances e.g chemicals, metals or preservatives
Kinesiology
- A holistic approach where muscle strength is assessed in response to exposure to specific substances
Common Intolerances Tested:
Food Intolerances:
- Lactose: Difficulty digesting milk sugar
- Gluten: Sensitivity to wheat proteins, distinct from coeliac disease
- Fructose: Malabsorption of fruit sugar
- Histamine: Sensitivity to high-histamine foods like ages cheese, wine or fermented products
- Food Additives: Reaction to preservatives, colourings or flavour enhancers like MSG
Chemical Intolerances:
- Intolerances to substances like fragrance, cleaning products or pollutants
Types of Allergy Testing:
Skin Tests:
- These are the most common and accurate methods for diagnosing allergies
Skin Prick Test (SPT):
- A small amount of suspect allergen is applied to the skin, which is then lightly pricked or scratched. If a raised, red bump (wheel) develops, it indicates a possible allergy
Intradermal Test:
- A small amount of allergen is injected under the skin. This is more sensitive than the prick test but has a higher rate of false positives
Patch Test:
- Allergens are applied to adhesive patches placed on the skin for 48 hours. This test is used for contact allergens like metals, fragrance or latex
Blood Tests:
- Measures the presence of allergen specific IgE antibodies in the blood. Common Tests include:
Common Allergies Tested:
- Environmental Allergens: Pollen, mold, dust mites, pet dander
- Food Allergens: Peanuts, tree nuts, eggs, milk, shellfish, soy, wheat
- Insect Allergens: Bee or wasp venom
- Medications: Penicilin, aspirin
- Chemical Allergens: Detergents, perfumes, latex