Food Intolerance (IgG Panel)

A food intolerance test measuring immunoglobulin G (IgG) antibody levels against a broad panel of common foods. Unlike IgE-mediated allergies which produce immediate reactions, IgG-associated food intolerances typically cause delayed symptoms appearing hours to days after consumption — including bloating, headaches, fatigue, skin issues, and digestive discomfort. The test identifies foods that produce elevated IgG responses, providing a starting point for elimination and reintroduction dietary strategies.

The Food Intolerance IgG Panel at Blessono Specialist Clinic measures immunoglobulin G antibody levels against a broad panel of foods from a single blood draw, helping identify foods that may be contributing to chronic, delayed-onset symptoms. IgG-mediated food reactions differ fundamentally from IgE allergies. While IgE responses are immediate (within minutes) and often dramatic (hives, swelling, anaphylaxis), IgG-associated food intolerances are delayed — symptoms may appear 4 to 72 hours after eating the trigger food, making identification through observation alone extremely difficult. Common symptoms associated with elevated IgG food reactivity include bloating, abdominal discomfort, gas, irregular bowel patterns, headaches, fatigue, brain fog, joint aches, and skin conditions such as eczema or acne. The panel tests reactivity to a comprehensive range of foods across major categories: dairy products (cow's milk, casein, whey, goat's milk, cheese), grains and cereals (wheat, gluten, barley, oats, corn, rice), proteins (chicken, beef, pork, lamb, fish, shellfish, eggs), legumes and nuts (soy, peanut, almond, cashew, lentils), fruits and vegetables (tomato, potato, banana, citrus, berry varieties), and common additives and flavourings. The blood draw is quick and the total appointment time including registration is approximately 30 minutes. Results are typically available within 5 to 10 working days and are presented in a clear report categorising each food by IgG reactivity level — typically traffic-light coded from no reaction (green) through moderate (amber) to high (red) reactivity. The follow-up consultation is a critical part of the service. The medical team helps patients interpret the results in the context of their symptoms and dietary habits, and designs an elimination protocol. The standard approach involves removing high-reactivity foods for four to six weeks, monitoring symptom improvement, then systematically reintroducing foods one at a time to identify which removals had the most impact. It is worth noting that elevated IgG levels to foods may simply reflect recent exposure rather than clinical intolerance, and the medical community has varying views on the predictive value of IgG testing. Blessono's physicians present the results as one data point within a broader clinical picture rather than as a definitive diagnosis, and the elimination-reintroduction protocol is the practical tool for confirming genuine intolerances.