Results of patch testing with five fragrance materials hitherto not tested: A dose-finding study in the clinical population

BACKGROUND

Quantitative risk assessment (QRA) for skin sensitization is used to derive safe use levels of sensitising fragrance ingredients in products. Post-marketing surveillance of the prevalence of contact allergy to these ingredients provides relevant data to help evaluate the performance of these measures.

OBJECTIVES

To determine a suitable patch test concentration for five fragrance materials that had hitherto not been tested on a regular basis. These concentrations are then to be used in a surveillance study with patch testing consecutive patients over an extended monitoring period.

MATERIALS AND METHODS

Furaneol, CAS.3658-77-3; trans-2-hexenal, CAS.6728-26-3; 4,8-dimethyl-4,9-decadienal, CAS.71077-31-1; longifolene, CAS.475-20-7; benzaldehyde, CAS.10052-7, were patch tested with other fragrance allergens in four clinics. Patch testing was conducted in three rounds, starting with the lowest concentrations of the five ingredients. The doses were increased in the subsequent rounds if no late-appearing positive reactions and virtually no irritant reactions were reported.

RESULTS

Overall, 373 patients were tested. No positive allergic reaction was reported to the five ingredients. Patch test results of other fragrance allergens are reported.

CONCLUSIONS

The highest test concentrations are each considered safe for patch testing consecutive patients. Further surveillance based on these preparations will evaluate the hypothesis that QRA-driven consumer product levels of these fragrances can prevent sensitization.

Importance of Supplemental Patch Testing Beyond a Screening Series for Patients With Dermatitis: The North American Contact Dermatitis Group Experience

IMPORTANCE

Patch test screening series for patients with dermatitis are limited and may miss clinically relevant contact allergens.

OBJECTIVE

To characterize individuals with dermatitis who showed clinically relevant patch test findings to supplemental (nonscreening) allergens or substances.

DESIGN, SETTING, AND PARTICIPANTS

A 17-year, retrospective cross-sectional analysis (January 1, 2001, to December 31, 2018) of North American Contact Dermatitis Group (NACDG) data from multiple centers in North America was conducted. A total of 43 417 patients with dermatitis underwent patch testing to the NACDG screening series in a standardized manner with 65 to 70 allergens and supplemental allergens as clinically indicated. Patients with 1 or more clinically relevant reactions to a supplemental (nonscreening) allergen/substance were analyzed between November 18, 2020, and March 12, 2021.

MAIN OUTCOMES AND MEASURES

The main outcomes were to assess the number of patients with clinically relevant reactions to supplemental (nonscreening) allergens and compare characteristics (including demographic characteristics and occupations) between patients with a clinically relevant patch test reaction to 1 or more supplemental allergens or substances (supplement-positive) and those without a reaction (supplement-negative) using odds ratios (ORs) and 95% CIs. Secondary outcomes included sources of allergic contact dermatitis and, for occupationally related cases, specific occupations and industries.

RESULTS

Of 43 417 patients included in the study who underwent patch testing to the NACDG screening series (65-70 allergens), 9507 individuals (21.9%) had currently relevant reactions to 1 or more supplemental allergens or substances. Of these, 6608 were women (69.5%) and the mean (SD) age was 47.2 (0.54) years. Compared with patients who had supplement-negative results, patients with supplement-positive findings were significantly less likely to be male (OR, 0.90; 95% CI, 0.85-0.94; P < .001) and/or have atopic dermatitis (OR, 0.89; 95% CI, 0.84-0.93; P < .001). Common primary sites of dermatitis in 9499 patients with supplement-positive findings included the face (2856 [30.1%]), hands (2029 [21.4%]), and scattered/generalized distribution (1645 [17.3%]). Frequent sources of supplemental allergens in 9235 patients included personal care products (4746 [51.4%]) and clothing/wearing apparel (1674 [18.1%]). Of 9362 patients with available data, supplemental allergens/substances were occupationally related in 1580 (16.9%); of those with identified occupations, 25.1% (384 of 1529) were precision production, craft, or repair workers. Of 9507 patients with supplement-positive findings, 2447 (25.7%) had no currently relevant reactions to NACDG screening allergens.

CONCLUSIONS AND RELEVANCE

This cross-sectional study found that 21.9% of patients who underwent patch testing to an allergen screening series of 65 to 70 allergens had at least 1 relevant reaction to supplemental allergens/substances. Of these, one-quarter reacted only to a supplemental allergen/substance. Screening series include common, important allergens, but these findings suggest that the addition of specialty allergens and personal or work products is critical for the successful diagnosis and management of allergic contact dermatitis.

Ultraviolet filter, fragrance and preservative allergens in New Zealand sunscreens

BACKGROUND/OBJECTIVES

Allergic contact dermatitis, photoallergic contact dermatitis and irritant reactions to sunscreens are common reasons for dermatology consultation. Patch testing for contact allergy relies on up-to-date knowledge of allergen exposures. The aim of this study was to investigate contact allergens and photoallergens in sunscreens commercially sold on the shelves of supermarkets and pharmacies in New Zealand.

METHODS

A comprehensive market data review of suppliers' websites was performed from March to August 2019 to obtain a list of the commonly sold sunscreens in our region. Ingredients were collated and analysed according to International Nomenclature of Cosmetic Ingredients (INCI) names. Ultraviolet (UV) filters, preservatives and fragrances were included for analysis. Place of sale and cost of sunscreens were also recorded.

RESULTS

Ninety-five sunscreens were analysed: 36% sold in supermarkets, 43% in pharmacies and the remainder available in both. The most frequent UV filters were butyl methoxydibenzoylmethane (contained in 70% of products) followed by octocrylene (63%) and homosalate (50%). The common photoallergen benzophenone 3 was found in 19% of products. Phenoxyethanol was the most common preservative (68%) followed by disodium EDTA (30%) and propylparaben (26%). Two sunscreens contained methylisothiazolinone. Sixty-one per cent contained at least one fragrance, the most frequent being limonene (17%) and linalool (13%). There was an average of 1.1 New Zealand baseline series allergens per product (range 0 to 6, standard deviation 1.27).

CONCLUSION

Common allergens including those with high sensitising potential were frequently found in New Zealand sunscreen. Knowledge of ingredients used by manufacturers is useful in dermatological assessment of skin contact reactions.

A baseline patch test series for New Zealand

BACKGROUND

Patch testing is the gold standard diagnostic test for allergic contact dermatitis and needs to be relevant to the region and the population being tested. The aim of this study was to develop a specific New Zealand baseline series (NZBS).

METHOD

We performed a retrospective case note review of patients attending four regional patch test centres between 2008 and 2020. Demographic and diagnostic information was collected for each patient along with results of patch testing. Using the results of this review, a group of 11 dermatologists with an interest in contact dermatitis agreed on a core group of allergens for inclusion in an NZBS, based on the frequency of positive reactions and allergens of interest. The remaining potential allergens were ranked by each dermatologist using an online questionnaire, with inclusion in the final NZBS by consensus.

RESULTS

Results from 2402 patients (67% female, mean age 44 years) from Auckland, Wellington, Palmerston North and Christchurch were collated. The 10 most frequent positive (relevant and non-relevant) allergens were nickel sulfate (22.0%), fragrance mix I (8.6%), cobalt chloride (7.3%), Myroxylon pereirae (5.6%), colophonium (5.1%), p-phenylenediamine (4.9%), methylisothiazolinone/methylchloroisothiazolinone (4.1%), fragrance mix II (3.9%), potassium dichromate (3.5%) and methylisothiazolinone (3.4%). Based on these results, a core series of 30 allergens was developed, with an additional 30 allergens added to form the extended series (total 60 allergens).

CONCLUSION

The baseline series of patch test allergens for routine use in New Zealand (NZBS) is based on national patch test data and expert consensus.