Latin name: Mentha piperita
Family: Lamiaceae (former Labiatae)
Common names: Mint, Peppermint, American Mint, Brandy Mint, Lamb Mint
Only a single serum-specific IgE test is available for the genus Mentha, and this is Mint f332 for Mint/Peppermint (Mentha piperita). However, a number of other Mint species and varieties are closely related, and there is even much uncertainty about the taxanomical boundaries. Mints should be considered as a group, especially since allergy may occur to derivatives such as menthol, which may come from a number of species.
Here are a few of the other important Mints:
- Common Mint/Field Mint/Wild Mint - Mentha arvensis
- Spearmint - Mentha spicata
- Ginger Mint - Mentha gentilis
- Orange Mint or Bergamot Mint - Mentha aquatica var. citrata
- Pennyroyal Mint - Mentha pulegium.
A herb, which may result in allergy symptoms in sensitised individuals.
Allergen ExposureGeographical distribution
The Mint family consists of fragrant aromatic plants of which the culinary and medicinal uses go back many centuries. More than 30 varieties can be obtained with different "flavours": apple, pineapple, lemon, and others. But the 3 chief species of Mint in cultivation and general use are the following: Spearmint (Mentha viridis), Peppermint or Mint (M. piperita), and Pennyroyal (M. pulegium).
Mint is a small, herbaceous perennial (0.3 m by 1 m), with a strong, fresh scent. It has lance-shaped, serrate leaves growing in opposite pairs along the stem, and flowers with unusual projecting stamens.
Mint grows wild in moist conditions, especially along banks and shores, waste seepage areas and wet meadows.
The aromatic leaves, with their strong yet pleasant taste and odour, were widely used for centuries. Tea was made from either fresh or dried leaves and hot water. This tea was also taken as a medicine for pain, colds, fevers, swellings, and colic. The leaves may be eaten raw or cooked and are used as a flavouring in salads and cooked foods.
Peppermint oil is derived from Mint and has many uses, chiefly as a flavourant but also in complementary and alternative medications for allergy (1). Menthol (also known as Mint camphor or Peppermint camphor) is a white, crystalline, aromatic substance, extracted from Peppermint oil or other Mint oils or made synthetically by hydronisation of thymol. Menthol is one of the most important flavouring chemicals. It is used extensively 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 found as an additive in some cigarettes, both for flavour and to reduce the throat and sinus irritation caused by smoking (2).
See under Environment.
No allergens from this plant have yet been fully characterised.
Potential Cross-ReactivityAn extensive cross-reactivity among the different individual species of the family, particularly within the genus Mentha, could be expected (3) 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; tests were negative with Basil and lavender and positive with all the others when the prick by prick technique was used. Serum-specific IgE was detected to all herbs tested. 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 (4).
Three naturally occurring substances in Peppermint have been reported to have sensitising properties: alpha-pinene, limonene, and phellandrene; these occur in colophony, balsam of Peru, turpentine peroxides, turpentine oil, and Peppermint oil (5).
Clinical ExperienceIgE-mediated reactions and contact dermatitis
Mint may uncommonly induce symptoms of food allergy or cutaneous allergy in sensitised individuals (6-7) 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 2 Florida bartenders who made drinks containing the leaves of Peppermint. Both were able to tolerate Spearmint (M. spicata) (8).
The vast majority of recorded reactions, however, involve not Mint itself but Mint derivatives used as flavourants, particularly menthol and oil of Peppermint. Candies, toothpastes and cigarettes are major sources of these allergens. Toothpastes may the most important sources, though establishing this would be complicated by the inclusion of other allergenic flavourants (e.g., cinnamic aldehyde and cinnamon oil), as well as preservatives.
Oil of Peppermint and Spearmint, carvone and anethole, all of which come from Mints, are ingredients with a low sensitising potential, but they are used in almost every brand of toothpaste. Stomatitis, cheilitis, glossitis, gingivitis, perioral dermatitis and immediate hypersensitivity from toothpaste containing Mint substances as flavourants have been reported (9-10). Similarly, 7 cases of contact allergy in a 6-year period were reported from a hospital clinic (11). In yet another study, toothpaste flavours have been reported as a cause of allergic contact dermatitis (11).
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. Patch testing indicated sensitisation to terpene ketone L-carvone, a substance occurring naturally in many Mint and Peppermint oils. In this instance, it resulted in recurrences of symptoms when the patient sucked refreshment lozenges containing L-carvone. L-Carvone is also contained in most chewing gums, and the authors suggest that this allergen should therefore be considered as an aetiological agent in cases of cheilitis and stomatitis (12).
A 26-year-old woman presented with a 12-month history of persistent dermatitis of the lips. Patch testing was negative. Identification of the offending allergen occurred only following an acute flare-up immediately after dental treatment with a Mint-flavoured tooth cleaning powder. Skin-specific IgE was detected using Mint leaves (13).
Cheilitis has also been reported following excessive intake of Mint-flavoured sweets (14). Urticaria and asthma exacerbation were reported after the ingestion of menthol-containing lozenges (15). Contact urticaria from menthol has been reported from mentholated cigarettes, cough drops, aerosol room spray and topical medicaments. Generalised urticaria was also seen following oral challenge (16-17). A perioral eczema was due to menthol in cigarettes (18). Non-thrombocytopaenic purpura has also been attributed to menthol-containing cigarettes (19). Despite its high concentration in Peppermint oil (up to 75%), menthol was said not to be the main sensitiser (5).
Peppermint oil from fragrances can cause allergic contact dermatitis (20).
Contact dermatitis has been reported from Peppermint and menthol in a local action transcutaneous patch (21).
Other studies have focused more on flavouring agents in themselves than specific products. Allergic contact dermatitis has been reported as a result of menthol in 2 individuals: cheilitis of 2 years duration in a 64-year-old woman, and an 18-month history of eczema affecting the upper lip of a 62-year-old man. Patch tests for Peppermint and menthol were positive (22). Allergic contact dermatitis from menthol has been reported to result in stomatitis (17).
A report was published of12 cases of contact sensitivity to the flavouring agents menthol and Peppermint oil in patients presenting with burning mouth syndrome, recurrent oral ulceration or a lichenoid reaction. Five patients with burning mouth syndrome demonstrated contact sensitivity to menthol and/or Peppermint, with 1 patient sensitive to both agents, 3 positive to menthol only and 1 to Peppermint only. Four cases with recurrent intra-oral ulceration were sensitive to both menthol and Peppermint. Three patients with an oral lichenoid reaction were positive to menthol on patch testing, with 2 also sensitive to Peppermint. Nine of the 12 cases demonstrated additional positive patch test results (23).
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 (24). Menthol- and aspirin-induced asthma has been reported in another study (25).
Occupational allergy may occur. (See also above.) A former laboratory technician referred to a clinic, because of swelling of his tongue, lips, and gingival mucosa following a dental operation, was found to be sensitised to colophony, balsam of Peru, turpentine peroxides and Peppermint oil (an ingredient of several dental preparations). This was established by patch testing (5). Allergic contact dermatitis has also occurred in food handlers (26). Making Mint sauce can result in skin reactions (27).
In a study of allergic and pseudo-allergic reactions in penicillin factory workers exposed to the dust of preparations of penicillin derivatives, histamine release caused by cocoa and Peppermint were demonstrated and reported to depend on non-immunological mechanisms, i.e., pseudo-allergic reactions (28).
A report stated that "refractory" gastrointestinal disorders may be as a result of frequent and large use of products containing Peppermint, and in the case of "dietetic" Mint, include sorbitol. Adverse conditions include stomatitis, severe esophagitis, esophageal ulcer, hiatal hernai, gastritis, unexplained diarrhoea, and recurrent pancreatitis. Some of these symptoms may be as a result of Peppermint decreasing lower esophageal sphincter pressure thereby facilitating eophageal reflux (29).
- Bielory L. Complementary and alternative interventions in asthma, allergy, and immunology. Ann Allergy Asthma Immunol. 2004 Aug;93(2 Suppl 1):S45-54.
- Hopp R. Menthol: its origins, chemistry, physiology and toxicological properties Rec Adv Tobacco Science 1993;19:3-46
- Yman L. Botanical relations and immunological cross-reactions in pollen allergy. 2nd ed. Pharmacia Diagnostics AB. Uppsala. Sweden. 1982: ISBN 91-970475-09
- Benito M, Jorro G, Morales C, Pelaez A, Fernandez A. Labiatae allergy: systemic reactions due to ingestion of oregano and thyme. Ann Allergy 1996;76(5):416-8
- Dooms-Goossens A, Degreef H, Holvoet C, Maertens M. Turpentine-induced hypersensitivity to peppermint oil. Contact Dermatitis 1977;3(6):304-8
- Schempp CM, Schopf E, Simon JC. Plant-induced toxic and allergic dermatitis (phytodermatitis). [German] Hautarzt 2002;53(2):93-7
- Fleming CJ, Forsyth A. D5 patch test reactions to menthol and peppermint. Contact Dermatitis 1998;38(6):337
- Sams W M. Occupational dermatitis due to mint Arch Dermatol 1940:41:503-505
- Sainio EL, Kanerva L. Contact allergens in toothpastes and a review of their hypersensitivity. Contact Dermatitis 1995;33(2):100-105
- Lewis FM, Shah M, Gawkrodger DJ. Contact sensitivity to food additives can cause oral and perioral symptoms. Contact Dermatitis 1995;33(6):429-30
- Andersen KE. Contact allergy to toothpaste flavors. Contact Dermatitis 1978;4(4):195-8
- Hausen BM. Toothpaste allergy. [German] Dtsch Med Wochenschr 1984;109(8):300-2
- Holmes G, Freeman S. Cheilitis caused by contact urticaria to mint flavoured toothpaste. Australas J Dermatol 2001;42(1):43-5
- Rogers SN, Pahor AL. A form of stomatitis induced by excessive peppermint consumption. Dental Update 1995;22(1):36-7
- Marlowe KF. Urticaria and asthma exacerbation after ingestion of menthol-containing lozenges. Am J Health Syst Pharm 2003;60(16):1657-9
- Papa C M, Shelley W B. Menthol hypersensitivity. J Am Med Assoc 1964:189:100-102.
- McGowan EM. Menthol urticaria. Arch Dermatol 1966;94(1):62-3.
- Camarasa G, Alomar A. Menthol dermatitis from cigarettes Contact Dermatitis 1978:4:169-170.
- Highstein B, Zeligman I. Non-thrombocytopenic purpura caused by mentholated cigarettes JAMA 1951:146: 816.
- Calnan C D. Oil of cloves, laurel, lavender, peppermint. Contact Dermatitis Newsletter 1970:7;148.
- Foti C, Conserva A, Antelmi A, Lospalluti L, Angelini G. Contact dermatitis from peppermint and menthol in a local action transcutaneous patch. Contact Dermatitis 2003;49(6):312-3
- Wilkinson SM, Beck MH. Allergic contact dermatitis from menthol in peppermint. Contact Dermatitis 1994;30(1):42-3.
- Morton CA, Garioch J, Todd P, Lamey PJ, Forsyth A. Contact sensitivity to menthol and peppermint in patients with intra-oral symptoms. Contact Dermatitis 1995;32(5):281-4
- dos Santos MA, Santos Galvao CE, Morato Castro F. Menthol-induced asthma: a case report. J Investig Allergol Clin Immunol 2001;11(1):56-8
- Kawane H. Menthol and aspirin-induced asthma. Respir Med 1996;90(4):247
- Peltonen L, Wickstrom G, Vaahtoranta M. Occupational dermatoses in the food industry. Dermatosen 1985:33:166-169.
- Tomson N, Murdoch S, Finch TM. The dangers of making mint sauce. Contact Dermatitis 2004;51(2):92-3.
- Mooller NE, Skov PS, Norn S. Allergic and pseudo-allergic reactions caused by penicillins, cocoa and peppermint additives in penicillin factory workers examined by basophil histamine release. Acta Pharmacol Toxicol (Copenh) 1984;55(2):139-44
- Roberts HJ. Caution regarding peppermint mints. South Med J 1983;76(10):1331