The use of carvone in consecutive patch testing

Abstract

Background: Carvone (l-carvone) is a mint-tasting flavour additive that most of us is exposed to and can cause allergic contact reactions.Objectives: To analyse the frequency and the relevance of positive carvone reactions in a dermatitis population.Method: A retrospective analysis of dermatitis patients consecutively tested with carvone from 2017 to 2021. Data were retrieved from the department's patch-test database.Results: Of 3554 patients tested with carvone, 28 (0.79%) had a positive reaction.Carvone-positive patients had higher mean age, were significantly more likely female (p < 0.001) and had often an intraoral/lip involvement (p < 0.001). In the carvonepositive group, 50% (n = 14) had a relevant reaction, and in 4 of 14, the relevance was first revealed after test reading. Of the carvone-positive patients, 18 of 28 did not have a coexisting allergy to a fragrance/flavour allergen and of these 44% had a relevant allergy. Conclusions:The study suggests that a significant fraction of relevant carvone contact allergies may be overlooked if the allergen is not tested. Furthermore, as the exposure is widespread, inclusion of carvone in the Swedish baseline series may be justified even if the contact allergy prevalence is below 1%.

Prevalence and causative allergens of contact cheilitis in Thailand

“…The literature has highlighted these substances as allergens responsible for cheilitis. 2,30 A recent study from Australia reported a high rate of relevant reactions to peppermint oil (5 out of 61) and spearmint (4 out of 61). However, we did not find positive reactions to menthol and peppermint oil in our study.…”

“…Mint flavours, such as menthol, peppermint oil, spearmint oil and L‐carvone are commonly used in toothpastes. The literature has highlighted these substances as allergens responsible for cheilitis 2,30 . A recent study from Australia reported a high rate of relevant reactions to peppermint oil (5 out of 61) and spearmint (4 out of 61).…”

“…The discrepancy in results may be due to differences in exposure between countries. While L‐carvone is an uncommon and weak allergen, contact allergy to it has been increasing over the past 5 years according to a Swedish study, likely due to daily exposure 30 . However, further studies are needed to confirm the association between this allergen and cheilitis.…”

Dill

“…64 In light of evidence that apiole may have abortion-inducing effects, it is recommended that apiole-rich essential oils be avoided during pregnancy and breastfeeding. 65,66 There are reports of carvone-associated contact allergenicity, [67][68][69][70][71][72][73][74][75][76][77][78] including several due to use of carvonecontaining toothpastes and other personal care products. A different concern arose from 1 small observational study in Turkey of patients with thyroid disease in which a decrease in thyroid hormone levels and an increase in thyroid nodule volumes were detected for those consuming 100-g dill.…”

“…There are reports of carvone-associated contact allergenicity, 67–78 including several due to use of carvone-containing toothpastes and other personal care products. A different concern arose from 1 small observational study in Turkey of patients with thyroid disease in which a decrease in thyroid hormone levels and an increase in thyroid nodule volumes were detected for those consuming 100-g dill 79 .…”