A Case of Type I Food Allergy Induced by Monosodium Glutamate

Abstract

Monosodium glutamate (MSG), a salt form of a non-essential amino acid, is widely used as a food additive, particularly in Asian cuisines, due to its unique flavor-enhancing qualities. Type I allergic reactions to MSG have not previously been reported. Our patient, a 21-year-old woman, was 14 years old when she first noticed swelling of her tongue (but no oral itching, diarrhea, or abdominal pain) after eating various snack foods. Current skin prick testing elicited a weak positive reaction to MSG. We then performed an oral challenge test during which our patient ingested potato snacks. Subsequent histology showed telangiectasia of the buccal mucosa, interstitial edema in the subepithelial submucosa, and mast cell infiltration. Oral mucosal challenge tests using sodium glutamate confirmed oral swelling in this patient. This report is the first to confirm a case of type 1 allergy to MSG by combining pathology findings with the results of challenge testing.

Keywords:

• food additive
• mast cell
• monosodium glutamate
• food allergy

Consent for Publication

Written informed consent was obtained from this patient.

Disclosure

No author has any conflict of interest to disclose for this work.

Additional information

Funding

The work was not funded by a grant or any other external source of financial support.