Question 1

What is the difference between a true allergy and a sensitivity?

Accepted Answer

A true allergy involves a specific IgE-mediated immune response — the immune system produces IgE antibodies against a specific substance (allergen), and subsequent exposures trigger mast cell degranulation causing rapid symptoms including hives, swelling, respiratory symptoms, or in severe cases anaphylaxis. A sensitivity (or intolerance) typically involves a non-IgE-mediated mechanism — such as enzyme deficiency (lactose intolerance), gut irritation, or immune activation without IgE — producing delayed symptoms that are generally less severe. The distinction matters clinically as management differs significantly.

Question 2

Can food sensitivities be tested accurately?

Accepted Answer

IgE allergy testing (skin prick test or specific IgE blood test) has good evidence for diagnosing IgE-mediated food allergies. IgG food antibody testing — offered by many private practitioners — measures IgG antibodies to foods, but the clinical significance of these is contested; IgG to foods is a normal immunological response to eating and does not reliably indicate food sensitivity. The most reliable way to identify food sensitivities remains a structured elimination and reintroduction protocol under professional guidance.

Question 3

Can allergies and sensitivities be outgrown?

Accepted Answer

Yes — many childhood food allergies (particularly to milk, egg, soy, and wheat) are outgrown by school age. Peanut, tree nut, fish, and shellfish allergies are more likely to persist into adulthood. Oral immunotherapy (a form of structured desensitisation) is increasingly available for peanut allergy and is showing promise for other food allergies. Allergic rhinitis and skin test positivity to environmental allergens can reduce over decades. Food sensitivities (non-IgE) often resolve with gut healing and dietary rotation approaches.

Question 4

Does gut health affect allergy development and severity?

Accepted Answer

The gut microbiome plays a central role in immune education and allergy susceptibility. Research consistently shows that reduced microbiome diversity in early childhood — linked to antibiotic use, caesarean birth, formula feeding, and reduced environmental microbial exposure — increases allergy risk. The "old friends" hypothesis proposes that reduced exposure to beneficial environmental microorganisms reduces immune tolerance training. Probiotic supplementation in pregnancy and infancy has modest evidence for reducing eczema and possibly other allergic conditions. Gut healing and microbiome support may also reduce adult allergy severity.

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Inflammation

Allergies

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