Contact sensitivity to oak moss

Are atranols the only skin sensitizers in oakmoss? A systematic investigation using non-animal methods

Oakmoss and treemoss absolutes are the major natural extracts of concern as potential sources of skin sensitizers in cosmetics and personal care products (PCP). Two single constituents, atranol and chloroatranol, have been identified as primary culprits in both lichens, and industrial self-regulation has been proposed to limit their contents to less than 100 ppm. Nonetheless, evidence points to the presence of additional candidate skin sensitizers in these multicomponent extracts. These observations, along with a lack of data from non-animal alternative methods and the chemical variability of commercial absolutes, prompted further investigation of oakmoss absolute along with altranol-like compounds in these extracts. The major chemical constituents of a commercial sample were identified by two independent analytical techniques, GC-MS and HPLC-DAD-MS. The crude oakmoss extract and pure compounds were assayed with two in chemico methods (HTS-DCYA and DPRA) to gauge their chemical reactivity. Activation of inflammatory responses in vitro was also investigated by KeratinoSens™ and human cell line activation tests (h-CLAT). Based on weight of evidence, orcinol, ethyl orsellinate, and usnic acid were classified as candidate sensitizers, along with both atranols and oakmoss extract.

Patch testing with serial dilutions and thin-layer chromatograms of oak moss absolutes containing high and low levels of atranol and chloroatranol

BACKGROUND

Oak moss absolute (Evernia prunastri extract) contains a large number of substances, among them the potent allergens atranol and chloroatranol. Since 2008, their content in oak moss absolute has been restricted by the International Fragrance Association to a maximum level of 100 ppm each.

OBJECTIVES

To compare the elicitation capacities of a traditional (sample A) and a treated (sample B) oak moss absolute containing, in total, 27 000 and 66 ppm of atranol and chloroatranol, respectively, and to investigate reactions to components of oak moss absolute separated by thin-layer chromatography (TLC).

METHODS

Fifteen oak moss-allergic subjects were patch tested with serial dilutions and TLC strips of samples A and B.

RESULTS

Fifteen subjects reacted to sample A at concentrations ≤ 2.0%, and 2 subjects reacted to sample B at 2.0% but not to lower concentrations. Among 13 subjects reacting to the TLC strip of sample A, 11 reacted to spots with retardation factor values corresponding to those of atranol and/or chloroatranol, and 11 reacted to other areas on the TLC strip. Only one subject reacted to the TLC strip of sample B.

CONCLUSIONS

The patch test reactivity of sample B was significantly lower than that of sample A. The TLC patch tests indicate the presence of sensitizers other than atranol and chloroatranol in oak moss absolute.

Allergic contact dermatitis from a natural deodorant: A report of 4 cases associated with lichen acid mix allergy

BACKGROUND

Botanical ingredients used in personal care products are a significant and underreported cause of allergic contact dermatitis.

OBJECTIVE

To evaluate allergic contact dermatitis from a widely-used botanical deodorant.

METHODS

We conducted patch testing in four patients who were using the botanical deodorant and were referred to the contact dermatitis clinic; three patients had axillary dermatitis and one had dermatitis of the external ear.

RESULTS

All four patients had positive patch test reactions to lichen acid mix and D-usnic acid. Of the three patients who were patch tested to the botanical deodorant, all had positive reactions.

LIMITATIONS

We did not test to the specific lichen used in the natural deodorant but rather used our own lichen acid mix and d-usnic acid in addition to testing to the actual product. One of the patients declined to be tested with the natural deodorant, but did test positive to the lichen acid mix and d-usnic acid.

CONCLUSION

Personal care products such as deodorants may represent a new route of exposure to lichen extract, a known allergen.

(22S)-6-O-ACETYL-21βH-HOPANE-3β,6β,22,29-TETROL FROM OAKMOSS (EVERNIA PRUNASTRI)

A novel hopanoid triterpene, (22S)-6-O-acetyl-21betaH-hopane-3beta,6beta,22,29-tetraol, was isolated from oakmoss (Evernia prunastri (L.) Ach.), as identified from 1H, 13C, DEPT, COSY, NOESY, HSQC and HMBC NMR, MS and IR spectroscopy. During recrystallisation a new compound, 30-nor-6-O-acetyl-3beta,6beta-dihydroxy-21alphaH-hopan-22-one, was formed by a formal loss of methanol from the dihydroxypropyl moiety. No biological activity was found for the naturally occurring compound upon testing against a series of fish and human pathogenic bacteria.

A liquid chromatography-mass spectrometric method for the determination of oak moss allergens atranol and chloroatranol in perfumes

This paper describes a validated liquid chromatographic-tandem mass spectrometric method for quantitative analysis of the potential oak moss allergens atranol and chloroatranol in perfumes and similar products. The method employs LC-MS-MS with electrospray ionization (ESI) in negative mode. The compounds are analysed by selective reaction monitoring (SRM) of 2 or 3 ions for each compound in order to obtain high selectivity and sensitivity. The method has been validated for the following parameters: linearity; repeatability; recovery; limit of detection; and limit of quantification. The limits of detection, 5.0 ng/mL and 2.4 ng/mL, respectively, for atranol and chloroatranol, achieved by this method allowed identification of these compounds at concentrations below those causing allergic skin reactions in oak-moss-sensitive patients. The recovery of chloratranol from spiked perfumes was 96+/-4%. Low recoveries (49+/-5%) were observed for atranol in spiked perfumes, indicating ion suppression caused by matrix components. The method has been applied to the analysis of 10 randomly selected perfumes and similar products.

Identification of atranorin and related potential allergens in oakmoss absolute by high-performance liquid chromatography-tandem mass spectrometry using negative ion atmospheric pressure chemical ionization

This paper describes the first high-performance liquid chromatographic-tandem mass spectrometric method for the identification of atranorin and related potential allergens in oakmoss absolute. Oakmoss absolute is ubiquitous in the fragrance industry and is a key component in many fine perfumes. However, oakmoss absolute causes an allergic response in some individuals. Research is focused toward establishing the identity of the compounds causing the allergic response so a quality controlled oakmoss with reduced allergenic potential can be prepared. Consequently a highly selective and specific analytical method is necessary to support this effort. This is not available with the existing HPLC methods using UV detection.

Adverse reactions to fragrances. A clinical review

This article reviews side-effects of fragrance materials present in cosmetics with emphasis on clinical aspects: epidemiology, types of adverse reactions, clinical picture, diagnostic procedures, and the sensitizers. Considering the ubiquitous occurrence of fragrance materials, the risk of side-effects is small. In absolute numbers, however, fragrance allergy is common, affecting approximately 1% of the general population. Although a detailed profile of patients sensitized to fragrances needs to be elucidated, common features of contact allergy are: axillary dermatitis, dermatitis of the face (including the eyelids) and neck, well-circumscribed patches in areas of "dabbing-on" perfumes (wrists, behind the ears) and (aggravation of) hand eczema. Depending on the degree of sensitivity, the severity of dermatitis may range from mild to severe with dissemination and even erythroderma. Airborne or "connubial" contact dermatitis should always be suspected. Other less frequent adverse reactions to fragrances are photocontact dermatitis, immediate contact reactions and pigmentary changes. The fragrance mix, although very useful for the detection of sensitive patients, both causes false-positive and false-negative reactions, and detects only 70% of perfume-allergic patients. Therefore, future research should be directed at increasing the sensitivity and the specificity of the mix. Relevance is said to be established in 50-65% of positive reactions, but accurate criteria are needed. Suggestions are made for large-scale investigation of several fragrances on the basis of literature data and frequency of use in cosmetics. The literature on adverse reactions to balsam of Peru (an indicator for fragrance sensitivity), essential oils (which currently appear to be used more in aromatherapy than in perfumery) and on fragrances used as flavours and spices in foods and beverages is not discussed in detail, but pertinent side-effects data are tabulated and relevant literature is provided.

Polymorphic light eruption with contact and photocontact allergy

We report a patient with long-standing polymorphic light eruption (PLE) who developed a photocontact allergy to mexenone and several contact allergies. The occurrence of multiple contact and photocontact allergies in PLE and the possible relationship of such allergies to the pathogenesis of PLE are discussed.