IgG test for children & teens – 270 foods (blood spot)

IgG is the most common antibody class in the blood. People who eat a food regularly often form IgG antibodies against its proteins. The EAACI task force describes these antibodies as a normal immune response to repeated contact with foods, and rather as a sign of tolerance than of hypersensitivity (PubMed 18489614).

A raised IgG value against a food therefore mainly means: this food has been eaten and recognised by the immune system. According to current knowledge it does not show that the food causes complaints. The German guideline states that IgG measurements cannot distinguish healthy from ill people (PubMed 34263109).

No. Foods that are eaten often – cow's milk, hen's egg, wheat and other gluten-containing grains – frequently show high values in IgG tests, including in people without complaints. A large study of over 21,000 adults found that IgG levels against foods vary widely in both healthy and symptomatic people and depend, among other things, on sex and region (PubMed 23301096). A German review names the many positive results in healthy people as the main problem of these tests (PubMed 20963379).

"Gluten IgG raised" is not a sign of coeliac disease either. Coeliac disease has its own medical blood tests (antibodies against tissue transglutaminase, IgA), which are only meaningful while gluten is being eaten (PubMed 31568151).

For each of the 270 foods the report shows a bar with the reaction level – none, weak, moderate or strong. The levels are based on the laboratory's cut-offs. There are no generally accepted cut-offs above which an IgG value is linked to complaints (PubMed 34263109).

The column "additional exclusions" groups related foods, for example different gluten-containing grains. The laboratory report speaks of "permitted" and "excluded" foods. This is the laboratory's way of presenting results, not a recommendation from ORY: professional societies advise against cutting out foods on the basis of IgG values (PubMed 20963379).

IgG4 is one of the four subclasses of IgG. Many food tests measure IgG4; according to its laboratory method, this test measures IgG (IgG ELISA). The same assessment applies to both: the German guideline recommends neither IgG nor IgG4 measurement against foods for diagnosing allergy or intolerance (PubMed 34263109).

According to the EAACI task force, IgG4 against foods rises mainly with repeated contact and is linked to tolerance (PubMed 18489614). The American Academy of Allergy, Asthma & Immunology (AAAAI) has endorsed this assessment (PubMed 20451986).

Food allergy: the immune system reacts to a food protein via IgE antibodies. Symptoms usually appear quickly, from itching in the mouth and rash to abdominal pain and severe reactions (anaphylaxis). In young children, milk and egg are the most common triggers (PubMed 34875122).

Intolerance: here the immune system is usually not involved. Often it concerns carbohydrates that are not fully absorbed in the small intestine, such as milk sugar (lactose) or fruit sugar (PubMed 27215624). Coeliac disease is a separate autoimmune disease triggered by gluten.

IgG against foods belongs to none of these groups. It shows contact, not disease (PubMed 18489614).

The assessment is clear:

• EAACI (European Academy of Allergy and Clinical Immunology): IgG4 food tests are not suitable for investigating allergy or intolerance and should not be performed for food-related complaints (PubMed 18489614).
• AAAAI (USA) supports this position paper (PubMed 20451986).
• German S2k guideline on IgE-mediated food allergy, led by the DGAKI together with other societies: IgG and IgG4 measurements against foods should not be performed to diagnose food allergy or intolerance – with strong consensus (PubMed 34263109).

The main reasons given are the many abnormal results in healthy people and the risk of unnecessary diets, which can reduce quality of life and lead to malnutrition (PubMed 20963379). We share this assessment and therefore offer the test only as information about antibodies, not as a diagnosis.

There are individual studies, mainly in irritable bowel syndrome in adults. In two randomised trials, participants cut out either foods with raised IgG or, for comparison, other foods; in the IgG group symptoms decreased somewhat more on average (PubMed 15361495, PubMed 39894284). The authors of the more recent trial consider larger studies necessary for confirmation.

These studies test a diet in a specific group, not whether IgG demonstrates an intolerance. So far they have not changed the assessment of the professional societies, and there are no such studies in children.

It starts with a medical history: what was eaten, and which complaints appeared when? If an allergy is suspected, IgE antibodies in the blood or skin tests follow, often a supervised challenge with the food (PubMed 34263109). Lactose intolerance can be checked with a breath test (PubMed 31427404), coeliac disease with blood antibody tests while gluten is being eaten (PubMed 31568151). For histamine intolerance and non-coeliac gluten sensitivity there are no established tests yet (PubMed 38068827).

Some of these examinations are also available with sample collection at home, such as the lactose breath test. An allergy, however, belongs in a paediatric or allergy practice, especially if reactions occur soon after eating.

The test shows against which of the 270 foods your child has IgG antibodies and how strongly. This can be information about previous eating habits and the immune system and a starting point for a conversation with the ORY expert team or with your doctor or naturopath, for example from the ORY expert network.

The test is not suitable for establishing an allergy, an intolerance, coeliac disease or the cause of complaints, and not as the sole basis for a change in diet (PubMed 34263109, PubMed 18489614).

In children, complaints after eating are often linked to foods. Research shows the following, with varying strength of evidence:

• Rash, hives, facial swelling, vomiting or breathing difficulty soon after eating: typical of an IgE-mediated allergy, in young children mainly to milk and egg – well established (PubMed 34875122).
• Recurrent abdominal pain: common in children, mostly functional abdominal pain without organic findings; diet, stress, infections and the gut-brain axis play a role – well described (PubMed 33154368).
• Abdominal pain, diarrhoea, poor growth or tiredness: can occur in coeliac disease; symptoms vary and are of limited value on their own (PubMed 31568151).
• Bloating, abdominal pain and diarrhoea after milk: in lactose intolerance; the link is well established, but self-assessment is often inaccurate (PubMed 31427404).
• Atopic dermatitis (eczema): elimination diets brought only slight improvement in studies and may increase the risk of true allergies (PubMed 35987995).
• Concentration problems, tiredness or skin irritation 4–72 hours after eating are often attributed to IgG. There is no evidence for this (PubMed 18489614).

These are associations from studies, not causes in your child. An IgG test cannot explain complaints and does not provide a diagnosis. Persistent complaints belong with the paediatrician first.

In case of breathing difficulty, wheezing, swelling of the tongue, lips or throat, sudden paleness or floppiness after eating, call the emergency number 112 immediately – these can be signs of a severe allergic reaction (PubMed 34343358).

Your child should see the paediatrician promptly in case of blood in the stool, persistent vomiting or diarrhoea, fever, weight loss or failure to gain weight, abdominal pain that wakes them at night, or if they restrict their eating more and more or are afraid of eating. If coeliac disease is suspected, do not cut out gluten before medical assessment, as the tests may otherwise be falsely normal (PubMed 31568151).

Please not without medical supervision. Children need enough energy, protein, calcium and other nutrients for growth and development. Even with proven allergies, children on restricted diets are at higher risk of nutrient deficiencies and poorer growth (PubMed 38280452). Cutting out foods without a proven allergy may also increase the risk of later developing a true allergy (PubMed 35987995).

This page does not give dietary advice. What makes sense for your child is something to discuss with the paediatrician or with the ORY expert team or with your doctor or naturopath, for example from the ORY expert network. The results consultation is included in the price.

According to the instructions the test is intended for children aged 3 and over; for younger children please speak to the ORY team first. Fasting is not required. Warm your child's hand well beforehand, clean the finger with the alcohol swab and let it dry completely. Place a drop of blood on the pre-punched field of the card and let it air-dry, then put it with the desiccant into the foil pouch and, together with the request form, into the postage-paid envelope. No cooling is needed.

IgG can only form against foods your child eats or has eaten. Please do not change their diet specially before the test, and do not stop prescribed medicines on your own.

The analysis usually takes 7–21 days from the sample's arrival at the laboratory. As soon as the report is ready, you will be notified. The results consultation with the ORY expert team is included in the price.

The IgG antibody test for children and adolescents costs €423.50 including VAT, shipping, return shipping and results consultation.

Statutory health insurance in Germany usually does not cover IgG food tests that you order yourself. With private insurance, reimbursement is possible but depends on your contract; how this works is described under "Reimbursement by private insurance".

For questions about an intolerance in children, other examinations arranged by the paediatrician are usually used. ORY offers, for example, the gut check-up for children and adolescents (€315), the basic vitamin check for children and adolescents (€106.50) and the lactose breath test (€65). The IgG antibody test for adults costs €385.

Which scope makes sense for your child can be clarified in the free initial consultation.