Is Your Reaction To Citric Acid a Sensitivity, Allergy or Something Else?

Did you know that citric acid occurs naturally and synthetically? For many people they probably never gave this a second thought.  For those who have the rare citric acid sensitivity or allergy, they will certainly have to give more thought to where to find it and how to avoid it.  This food sensitivity or allergy is not only very rare, but it is very difficult to diagnose and detect in traditional allergy skin tests.

The most difficult part of determining this sensitivity or allergy, is that citric acid is very commonly used as an ingredient as a food additive and preservative.  It is hard to isolate this as it is in many different processed foods.  The reactions one might experience can be minimal to severe, and should not be ignored. 

Here's what you need to know about citric acid and citric acid sensitivity or allergy.

Does Citric Acid Come from Citrus?

This is a complicated answer, as there are two ways that is exists.  Citric acid in its natural form is in fruits, and in this case most people have the allergy to the fruit, not to citric acid.  However, citrus fruits, such as oranges, lemons, and limes, can cause oral allergy syndrome or contact reactions in some people. The acid in citrus fruits can also aggravate acid reflux symptoms and cause some people to experience heartburn.

In its weak form, citric acid, from the natural form, can be used as a food additive.

It is often used to provide a sour or tart flavoring, act as a preservative or serve as an emulsifier.  It is often used in canned and jarred foods to prevent botulism and has been around for over 100 years. 

However, it is also produced synthetically. A synthetic form of citric acid has been developed by industrial manufacturers.

 This form has is created by using a type of mold called Aspergillus Niger, otherwise known as black mold. There have been controversial issues related to black mold, however this process uses a different and safer strain.  This has become a popular process as it is much cheaper to produce it this way than to use the natural version.

In the manufacturing process, the mold culture is fed sugar solutions, which are often derived from corn. Many people who react to foods containing citric acid may actually be allergic to the mold or the corn used to produce the acid.  In this form citric acid is a common food additive found in many processed foods.  Citric acid is found in foods like: ice cream, sorbet, caramel, soda, beer, wine, baked goods, processed sweets and pre-cut pre-packaged fruits and vegetables. Its role is to work as a preservative in these foods and to provide a longer shelf life.  

Symptoms of Citric Acid Sensitivity or Allergy

The symptoms of citric acid sensitivity may range from mild skin rashes to symptoms of a severe allergic reaction. Symptoms may include:

  • Mouth ulcers or rashes
  • Gastrointestinal symptoms, such as abdominal pain, bloating, or diarrhea
  • Swelling of the mouth or throat

Cross Reactions 

While you might think you are allergic to citric acid, it may actually be a reaction to mold or a corn issue.  If you have an allergy or sensitivity to airborne mold or mold found in the environment, you may also react to mold in or on the foods you eat. If you are allergic to corn, you may be sensitive to the tiny amount of corn that is left in citric acid during the manufacturing process.

Allergists can determine if you have an allergy to mold or corn using a skin-prick test, but to determine if you are also sensitive to mold in foods, you will need to do an elimination diet and supervised oral food challenge.

Some alternative medical practitioners believe that sensitivity to citric acid and other food additives is caused by exposure to environmental toxins. A build-up of heavy metals in the body is believed to lead to sensitivity to small quantities of additives that do not bother most other people.

Updated by: Marlo Mittler, MS RD


Schuster, E., Dunn-Coleman, N., Frisvad, J. C. & van Dijck, P. W. M. (2002) On the safety of Aspergillus Niger - A Review. Applied Microbiology and Biotechnology 59: 426-435.

Genuis, Stephen. Sensitivity-related illness: The escalating pandemic of allergy, food intolerance and chemical sensitivity. Science of The Total Environment, Volume 408, Issue 24, 15 November 2010, Pages 6047-6061

Luccioli, S. et al. Can Mold Allergy Be Triggered Via the Oral Route? Annals of Allergy, Asthma & Immunology, Volume 93, Issue 5, Supplement 3, November 2004, Page S55

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