Results of patch testing propolis in the European baseline series: A 4-year retrospective study.

BACKGROUND: Propolis was added to the European baseline series (EBS) in 2019. OBJECTIVES: To investigate the frequency and relevance of positive patch tests to propolis in the EBS and to study co-reactivities. PATIENTS AND METHODS: Retrospective study in patients patch tested between June 2019 and November 2023 in a university hospital in Amsterdam, The Netherlands. RESULTS: Of 3134 consecutive patients, 299 (9.5%) had a positive reaction to propolis 10% pet. Only nine reactions (3%) were judged to be clinically relevant. There were significant co-reactivities to Myroxylon pereirae resin (balsam of Peru), colophonium, fragrance mixes 1 and 2, and to limonene and linalool hydroperoxides. A steep increase in rates of positive reactions to propolis was observed from 2020 to 2023. This was highly likely the result of the replacement of Chinese propolis with Brazilian propolis by the manufacturer. CONCLUSIONS: Positive patch tests for propolis are very frequent in Amsterdam, but only a few of these reactions are relevant. Most are probably (pseudo-)cross-reactions in patients with fragrance allergies. Propolis in the EBS has very limited value for dermatologists and patients in The Netherlands. Changes in patch test materials should be provided to all users to avoid misinterpretation of patch test results.

Use of sorbitan sesquioleate in patch test preparations and patch testing with the substance-What do our results mean?

BACKGROUND: Sorbitan sesquioleate (SSO) is a sorbitan fatty acid ester, an emulsifier used in topical products and certain patch test preparations. SSO may affect the patch test results. It has been debated whether to include the substance in the baseline series to avoid misinterpretation of the results. OBJECTIVES: To report the prevalence and simultaneous reactions of SSO with other patch test preparations containing SSO as an emulsifier. MATERIALS AND METHODS: A retrospective analysis of 3539 dermatitis patients who underwent patch testing from 2016 to 2020 was performed. RESULTS: The 5-year SSO contact allergy prevalence was 0.48%, and 1.3% had a doubtful reaction. Patients with a stronger positive reaction (2+, 3+) were more likely to react simultaneously to other allergen preparations containing SSO (p value = 0.018). One patient with a strong reaction to SSO reacted positively to all SSO-containing patch test preparations. Definite fragrance allergens could not be identified in the patients who had simultaneous reactions to SSO and fragrance mix (FM) I. CONCLUSIONS: Patch testing with allergen preparations containing SSO affected the patch test interpretation. Fragrance contact allergy could not be ruled out when a patient simultaneously reacted to SSO and FM I. Changing emulsifiers in patch test preparations would be advantageous.

Simultaneous patch testing with fragrance markers in the baseline series and the ingredients of fragrance mixes: An update from southern Sweden.

BACKGROUND: Regularly updating the prevalence of fragrance contact allergy (CA) is important. Patch testing with fragrance markers in the baseline series and the ingredients of fragrance mixes (FMs) is still debated. OBJECTIVES: To update the prevalence and clinical characteristics of patients with fragrance CA. To establish the results of patch testing with individual allergens of FMs. METHODS: A retrospective analysis of 3539 patients with dermatitis who were patch tested with the baseline series and FMs ingredients during 2016 to 2020 was performed. RESULTS: The prevalence of fragrance CA was 13%. About 10% of these patients with fragrance CA would be missed if the individual ingredients were not tested. Unlike hydroxyisohexyl 3-cyclohexene carboxaldehyde, there was no decreasing trend of CA to Evernia prunastri (oakmoss) extract after the EU regulation came into force. Patients with CA from only one ingredient of the mixes or having a weak positive reaction to the ingredients were significantly missed when tested with only the fragrance markers in the baseline series. CONCLUSIONS: Patch testing with individual fragrance allergens is crucial for experts to expand knowledge in the fragrance CA field. The concentrations of the allergens in FMs may need to be adjusted to detect patients with fragrance CA, since some were significantly overlooked.

Prevalence, concomitant reactions, and factors associated with fragrance allergy in Thailand.

BACKGROUND: Fragrances are the most common cause of cosmetic contact allergy. Up-to-date information on contact allergy frequencies and relevance aids primary and secondary preventive measures. OBJECTIVES: To determine the prevalence, associated factors, and concomitant reactions in fragrance allergy among Thais. METHODS: This retrospective study collected data from 2012 to 2019. The patient characteristics of fragrance and nonfragrance allergy groups were compared. Concurrent positive reactions to fragrance allergens (fragrance mix [FM] I, FM II, Myroxylon pereirae resin and hydroxyisohexyl 3-cyclohexene carboxaldehyde) and other baseline-series allergens were analysed. RESULTS: Of 1032 patients, 175 (17.0%) had fragrance allergy, with 57.7% of clinical relevance. FM I showed the highest prevalence (9.4%). The associated factors were being elderly, lesions on the extremities, metal allergy history, and long dermatitis duration. Contact allergies to epoxy resin and Compositae plants were significantly associated with fragrance allergy with an odds ratio of 5.95 (95% confidence interval [CI]: 5.21-6.80) and an odds ratio of 4.42 (95% CI: 1.58-12.36), respectively. No significant associations between colophonium (previously proposed as a fragrance marker) and fragrance allergens were found. CONCLUSIONS: The prevalence of fragrance contact allergy remains high and should be considered in old patients presenting with long-standing eczema on the extremities. Unlike reports from other countries, varied, significant, concomitant reactions were observed.

Adding sorbitan sesquioleate to the European baseline series: Necessary, reasonable, or unavoidable?

Positive reactions to fragrance mix I (FM I) are frequent in consecutively patch tested patients suspected of having allergic contact dermatitis. However, the FM I test preparations contain 5% of the emulsifier sorbitan sesquioleate (SSO), and it is well known that SSO can cause contact allergic reactions in its own right. Indeed, the available data show that some patients with contact allergy to SSO react to FM I but are not allergic to fragrances. When SSO is not tested, this situation may go unnoticed, a wrong diagnosis of fragrance allergy may be given to the patient, and unjustified advice to avoid fragrances and fragranced products will be given in such cases. To avoid such suboptimal patient care, we postulate that testing with SSO in all patch tested individuals is mandatory. As it is well known that only a minority of FM I-reactive patients will undergo a breakdown test with the ingredients and SSO, testing with SSO in all patients can only be achieved by adding it to the European baseline series. Not testing with SSO may also result in misinterpretation of patch test reactions to Myroxylon pereirae resin and 2-hydroxyethyl methacrylate in the baseline series, as both (may) contain SSO, and, for the same reason, of reactions to several other hapten test materials.

Myroxylon pereirae resin (balsam of Peru) - A critical review of the literature and assessment of the significance of positive patch test reactions and the usefulness of restrictive diets.

In this article, contact allergy to Myroxylon pereirae resin (MP) (balsam of Peru) is reviewed. The topics presented include the uses, the chemical composition, the frequency of sensitization, the relevance of positive reactions, the MP-containing products causing allergic contact dermatitis, co-reactivity with other fragrance and non-fragrance materials, the sensitizers, the usefulness of MP as a "marker" of fragrance allergy, and the effectiveness of, and indications for, "balsam-restrictive" diets. Sensitization to MP occurs in 4% to 8% of patients routinely tested for suspected contact dermatitis. There are few adequate data on relevance. Topical pharmaceuticals were formerly, but are not today, important sources of sensitization. Cosmetics and foods or drinks are hardly ever products responsible for sensitization to MP. Positive patch test reactions in the large majority probably result from previous sensitization to MP constituents because of their presence in fragrances and fragranced products, MP thereby acting as marker (or "indicator") of fragrance allergy. However, fragrance mix I is a more sensitive marker, and the added diagnostic value of testing with MP is unknown. The allergenic ingredients of MP include isoeugenol, eugenol and cinnamyl alcohol, but there are other-largely unknown-chemicals that are responsible for contact allergy. Suggestions are given for further research to address questions thus far unanswered and to improve patient care.

Contact sensitization to ingredients of dental materials and cosmetics in dental students: a pilot study.

OBJECTIVE: The aim of this study was to evaluate the rate of contact sensitization to selected cosmetic allergens, i.e. ingredients of dental materials, in students of dental medicine and dental patients. METHODS: A total of 50 participants were included in the study: 40 students of dental medicine exposed to the studied allergens during the course of practical education; and 10 randomly selected dental patients without occupational exposure to the investigated substances served as a control group. All of them were patch-tested with colophonium, myroxylon pereirae resin, paraben mix, fragrance mix I, isopropyl myristate, triclosan, polysorbate 80, compositae mix II, and hydroperoxides of limonene. RESULTS: The sensitization rates for colophonium and polysorbate 80 were the highest. For the group of dental students, we established significantly higher sensitization rate for colophonium compared to the ones for myroxylon pereirae resin and hydroperoxides of limonene (χ2 = 4.93; p = 0.026), paraben mix (χ2 = 3.6; p = 0.05), isopropyl myristate (χ2 = 6.56; p = 0.01), and triclosan (χ2 = 8.5; p < 0.001); and to polysorbate 80 compared to the ones for myroxylon pereirae resin and hydroperoxides of limonene (χ2 = 3.97; p = 0.046), isopropyl myristate (χ2 = 5.47; p = 0.02) and triclosan (χ2 = 7.34; p = 0.007). Significantly increased concomitant sensitization rate to compositae mix and to hydroperoxides of limonene was established (χ2 = 12.55; p < 0.001). Generally, the incidence of concomitant sensitization to the studied allergens in the whole studied population was high. CONCLUSIONS: Colophonium and polysorbate 80 could be outlined as sensitizers of paramount importance for both dental students and dental patients. We consider the major importance of exposure to colophonium during the course of practical education in dentistry for the onset of the sensitization. Sensitization to compositae mix was observed only among dental students. We consider the leading role of consumer exposure for the onset of the sensitization to triclosan and to hydroperoxides of limonene. Unexpected and unreported reactions of concomitant sensitization were observed.