Type IV non-IgE-mediated allergy

This is a late-type allergy, based on allergen-specific T lymphocytes directed against food proteins. The reaction often does not appear until 24 to 48 hours after the meal.

The symptoms are just as complex, ranging from gastrointestinal inflammatory symptoms (leaky gut) to skin eczema and an increase in myalgic or arthritic symptoms.

Detection of T-cell sensitisation to a food is possible using the Lymphocyte Transformation Test (LTT). LTT is used in cases of food intolerance where the reaction only appears after several hours and persists for several days.