Mint is a food which may result in allergy symptoms in sensitised individuals.

Mint Allergy Test: Allergen Exposure

Mint is an aromatic plant which grows in moist conditions, particularly along riverbanks and shores and in wet meadows. It is widely used as a garnish, and the leaves can also be made into a tea.

Peppermint oil is derived from mint, and from this it is possible to extract a crystalline substance known as menthol. Menthol has a range of uses, principally as a flavouring in pharmaceuticals, cosmetics and toiletries – especially toothpastes – chewing gum, candies, and alcoholic drinks.

It is an important ingredient in sore throat remedies, and in creams for sore muscles, inhalers, and cooling gels.

It is also added to cigarettes, both to improve or mask the flavour and also to soothe irritation to the throat caused by tobacco smoke.

Mint Allergy Test: Allergen Description

No allergens present in mint have been fully characterised to date.

Mint Allergy Test: Potential Cross-Reactivity

An extensive cross-reactivity among the different individual species of the family, particularly within the genus Mentha, could be expected and has been suggested by clinical studies.

In a report describing 3 systemic allergic reactions caused by oregano and thyme in the same patient, skin-specific IgE tests with plants of the Lamiaceae family (hyssop, basil, marjoram, mint, sage, lavender, etc.) were all positive. The study concluded that “plants belonging to the Labiatae [Lamiaceae] family seem to show cross-sensitivity on the basis of clinical history and in vitro and in vivo test results”.

Mint Allergy Test: Clinical Experience

Mint may uncommonly induce symptoms of food allergy or cutaneous allergy in sensitised individuals but it is possible that the allergy occurs more frequently than reported.

Adverse events to menthol and peppermint oil, both compounds extracted from mint, have been more frequently reported, in particular in skin sensitisation.

Allergic contact dermatitis from mint was first described in 1940. Occupational allergic contact dermatitis was described in two Florida bartenders who made drinks containing the leaves of peppermint.

Stomatitis, cheilitis, glossitis, gingivitis, perioral dermatitis and immediate hypersensitivity from toothpaste containing mint substances as flavourings have been reported.

In a separate study, toothpaste flavours containing mint have been reported as a cause of allergic contact dermatitis.

Cheilitis was observed in a 74-year-old patient after use of a new toothpaste. The reaction occurred after several weeks despite withdrawal of the paste.

A 26-year-old woman presented with a 12-month history of persistent dermatitis of the lips. Identification of the offending allergen occurred only following an acute flare-up immediately after dental treatment with a mint-flavoured tooth cleaning powder.

Contact dermatitis has been reported from peppermint and menthol.

Menthol-induced asthma was described in a 40-year-old woman with no history of asthma or any other allergy who developed dyspnoea, wheezing and nasal symptoms when exposed to mentholated products such as toothpaste and candies.

Other reactions

A report stated that “refractory” gastrointestinal disorders may be as a result of frequent and large use of products containing peppermint. Adverse conditions include stomatitis, severe esophagitis, esophageal ulcer, hiatal hernia, gastritis, unexplained diarrhoea, and recurrent pancreatitis.