05 July 2011

Conditions that mimic food allergy

It is important to have a medical examination and allergy tests done to determine if you have a true food allergy as there are many other conditions that could mimic your symptoms.


It is important to have a medical examination and allergy tests done to determine if you have a true food allergy as there are many other conditions that could mimic your symptoms, says DietDoc.

I recently came across a fascinating article on “Mimics of Food Allergy” by Drs Michael Levin and Harris Steinman, two of South Africa’s leading allergologists, in the Current Allergy & Clinical Immunology Journal, which was so interesting that I would like to share its contents with Health24's readers. In this article, Drs Levin and Steinman list a variety of other medical conditions that can cause symptoms which are similar to those occurring with food allergy and may thus convince patients that they are suffering from a true food allergy when they are not.

Startling statistics

The authors state that up to 34% of patients or parents of paediatric patients, believe that they or their children suffer from food allergies, and 22% of these individuals avoid certain foods because of their belief. However, only between 1% and 6% of such persons actually test positive when they undergo allergy testing.

I have also noticed that many Health24 readers who write in for dietary advice, immediately suspect that they are allergic to a food if they display symptoms such as bloating, diarrhoea, sinusitis, skin rashes, acid reflux or nausea.

Other individuals say that they have removed certain foods such as milk from their children’s diets because of suspected (but unconfirmed) food allergy. What always worries me, is that in such cases, most parents do not consider what negative dietary effects the removal of such foods can have on the health of their children. For example, if one removes all milk and dairy products from a person’s diet, then care must be taken to compensate for the loss of these rich and highly bioavailable calcium sources by either substituting other food sources of calcium or providing a calcium supplement to keep the skeleton and teeth of growing children healthy.

Consequently it is always advisable to have a medical examination and tests done to determine if you, or your child, really have a true food allergy, before you remove whole food groups from your own, or your children’s diet. The chances are good that you, or your child, may not be allergic to foods and that one of the many other conditions outlined in the article by Drs Levin and Steinman (2009), could be the cause of the symptoms that prompted you to avoid these specific foods.

Psychological aversions

According to Drs Levin and Steinman (2009), psychological aversions to certain foods can occur in children younger than 2 years who will refuse such foods or vomit or gag when the food is offered to them. If the child then fails to thrive and becomes fractious and irritable, the frantic parents may believe that their child has a true food allergy which is making him/her react this way.

The authors point out that psychological food aversions are probably among the most difficult food reactions to diagnose and treat.

In rare cases, food aversions triggered by psychological factors can lead to paediatric anorexia and even influence adult eating patterns later in that person’s life. If your child refuses to eat certain foods and your paediatrician has eliminated food allergy as a cause, then it may be necessary to obtain assistance from a child psychologist or paediatric psychiatrist. Sometime family therapy may be indicated if the child is manifesting food aversions as a "silent cry for help" because of dysfunctional family dynamics.

Anatomical and digestive problems

A variety of anatomical and digestive problems, including hiatus hernia, gastric reflux, gastric ulcers, cancer, irritable bowel syndrome (IBS) and inflammatory bowel disease can also produce symptoms that may mimic food allergy. For example, any one of the above mentioned anatomical or digestive problems can cause nausea, flatulence, bloating, diarrhoea, dyspepsia, and pain.

In addition, patients with a condition such as IBS may tend to react to certain foods (e.g. very fatty or very spicy foods, foods that produce gas such as the cabbage family, legumes, the onion and garlic families, gas-containing drinks, alcohol, etc), thus strengthening the belief that the patient is ‘allergic’ to the given food or foods. Such patients require medical treatment for their IBS and should avoid the offending foods, but only under the guidance of a registered dietitian who will ensure that the patient’s diet does not become deficient because of cutting out the foods that trigger his or her IBS.

One of the reasons why it is important to have a medical examination if you suspect foods allergy, is that certain cancers and ulcers can cause similar symptoms (Levin & Steinman, 2009). These are serious medical conditions that require urgent treatment and which may go undetected if an individual does his or her own diagnostics.

Enzyme deficiencies

A lack of digestive enzymes can also cause food intolerance leading people to believe that they suffer from a true food allergy (Levin & Steinman, 2009). Patients can have deficiencies of a variety of enzymes, and suffer from related food intolerances, namely:

  • Lactose intolerance - leading to an inability to digest lactose, a sugar found in milk.
  • Fructose intolerance- characterised by problems with digesting fruit sugar or fructose, which is found in fruit, fruit juice and some foods that are sweetened with fructose, particularly diabetic products
  • Alcohol intolerance - inability to metabolise alcohol
  • Sulphite intolerance - reactions to foods containing sulphite as a preservative
  • Fava or broad bean intolerance - this intolerance is caused by a deficiency of the glucose-6-phosphate dehydrogenase (G6PD) enzyme
  • Galactosemia - patients develop reactions to foods that contain lactose from milk and galactose, a sugar found in legumes (dry beans, peas, lentils, soy)
  • Phenylketonuria - a deficiency of the enzyme phenylalanine hydroxylase leads to an inability to metabolise phenylalanine, an amino acid, which is found in high protein foods and is used in sweeteners such as aspartame

(Levin & Steinman, 2009)

A person who, for example, has a fructose intolerance can develop bloating, winds, cramps and diarrhoea, which could lead him or her to suspect a food allergy. In similar fashion, someone who always develops symptoms after eating legumes may not be truly allergic, but suffer from galactosemia due to deficiency of the G6PD enzyme.

The crux of the article by Drs Levin and Steinman (2009) is to underline that there are many different and divergent causes for the common symptoms that are so often ascribed to food allergy by the public. It is therefore important to have a medical examination and allergy tests if these should prove necessary, so that you can receive the correct treatment for your condition and that you do not just cut out whole food groups (and all the nutrients they contain), because of suspected, but undiagnosed food allergy.

- (Dr IV van Heerden, DietDoc, June 2011)                                                        


(Levin ME, Steinman H (2009). Mimics of food allergy. Current Allergy & Clinical Immunology, Vol 22(3):110-116)

Any questions? Ask DietDoc 

Read more:

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Allergy, intolerance: which is it?
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Dr Morris is the Principal Allergist at the Cape Town and Johannesburg Allergy Clinics with postgraduate diplomas in Allergology, Dermatology, Paediatrics and Family Medicine dealing with both adult and childhood allergies. obesity and diabetes societies and runs a trial centre for new drugs.

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