Allergens of Special Interest

Surveillance of contact allergies: methods and results of the Information Network of Departments of Dermatology (IVDK)

Contact allergy (CA) surveillance networks provide information to a multitude of stakeholders, which is indispensable for evidence-based decision-making in the field of prevention. Methods and results of the German surveillance system on CA are reviewed and discussed with reference to other systems. The German network structure comprises 56 departments of dermatology and includes all patients who are patch-tested for suspected CA. Data analysis considers the results of patch testing and further pertinent information for each patient. Following aspects are addressed: (i) the description of the clinical population, (ii) evaluation of patch test reactions, (iii) relationship between patch test results and population characteristics. Trend analyses on chromate (decreasing), epoxy resin (increasing) and nickel (heterogeneous) served as examples for surveillance system analyses, with the identification of sentinel events, as well as proof of success or failure of prevention. In addition, external data sources can be used such as sales data of patch test preparations to estimate frequencies of sensitization on a population level. National prescription data of drugs and statistics of labelling of preservatives on cosmetics can be included, the latter two approaches allowing for risk estimates conferred by specific allergens.

Predictive performance for human skin sensitizing potential of the human cell line activation test (h-CLAT)

BACKGROUND

Recent changes in regulatory restrictions and social opposition to animal toxicology experiments have driven the need for reliable in vitro tests for predicting the skin sensitizing potentials of a wide variety of industrial chemicals. Previously, we developed the human cell line activation test (h-CLAT) as a cell-based assay to predict the skin sensitizing potential of chemicals, and showed the correspondence between the h-CLAT and the murine local lymph node assay results.

OBJECTIVES

This study was conducted to investigate the predictive performance of the h-CLAT for human skin sensitizing potential.

MATERIALS/METHODS

We selected a total of 66 test chemicals with known human sensitizing potential, and tested all chemicals with the h-CLAT. We then evaluated the performance of the h-CLAT in predicting human sensitizing potential.

RESULTS AND CONCLUSION

Forty-five of 51 tested sensitizers were positive in the h-CLAT, indicating relatively high sensitivity. Also, 10 of 15 non-sensitizers were correctly detected as negative. The overall agreement between human data and h-CLAT outcome was 83%. Furthermore, the h-CLAT could accurately predict the human sensitizing potential of 23 tested chemicals that were amines, heterocyclic compounds, or sulfur compounds. Our data indicate the utility of the h-CLAT for predicting the human skin sensitizing potential of a variety of chemicals.

[Skin sensitizers in cosmetics and skin care products]

Cosmetics are defined as "articles with mild action on the human body, which are intended to be applied to the human body through rubbing, sprinkling or other methods, aiming to clean, beautify and increase the attractiveness, alter the appearance or to keep the skin or hair in good condition (The Pharmaceutical Affairs Law: Article 2)." Consequently, they include personal hygiene products such as shampoos, soaps and toothpaste. In Europe, 1% of the population is estimated to be allergic to fragrances and 2-3% to ingredients of cosmetics; 10% of outpatients patch-tested for cosmetics allergy were found to be positive. Allergenic ingredients of cosmetics can be fragrances, hair dye, preservatives, antioxidants, emollients, surfactants, UV absorbers, pigments or resins used in nail cosmetics. Among standard allergen series, eight substances are related to cosmetics; in Japan in 2003, p-phenylenediamine (hair dyes) induced allergic reactions with the highest rate of 7.9% in outpatients patch-tested (n=805), followed by fragrance mix No. 1 (4.0%, mixture of eight fragrances frequently used), colophony (3.2%, main contents of pine resin), lanolin alcohol (2.7%,emollients), and formaldehyde, parabens, Kathon CG (2.7% ,1.9% and 1.0%, respectively; preservatives). Cosmetic allergy symptoms tend to be mild except those caused by hair dye. However, the population exposed to cosmetics is huge and the number of ingredients used in cosmetics increased up to more than 6000. Here, major cosmetic ingredient allergens, mainly reported in Japan, are reviewed and discussed.

Potent skin sensitizers in oxidative hair dye products on the Swedish market

BACKGROUND

In recent years, the alarming increase in contact allergy to hair dyes has drawn much attention. It has been shown that many of the currently allowed hair dye substances are potent skin sensitizers.

OBJECTIVES

To study the prevalence of hair dye substances, categorized as potent skin sensitizer, in oxidative hair dye products on the Swedish market.

MATERIALS AND METHODS

Ingredient labels of 122 oxidative hair dye products from 20 brands were examined. All ingredients were recorded, and the prevalence of hair dye substances categorized as potent skin sensitizers was assessed.

RESULTS

According to ingredient labelling, 120 out of 122 examined oxidative hair dye products contained hair dye substances categorized as potent skin sensitizers. More than 80% of the products contained at least four such substances; 37 hair dye substances categorized as potent skin sensitizers were identified, and 10 of these were more prevalent than p-phenylenediamine.

CONCLUSIONS

Hair dye substances categorized as potent skin sensitizers are very common in oxidative hair dye products. A substantial number of potent skin sensitizers are more frequently used than p-phenylenediamine, while only a few are commercially available as patch test substances.

[Facial allergic contact dermatitis. Data from the IVDK and review of literature]

The face is exposed to many foreign substances and may thus be a site of allergic contact dermatitis. Our aim is to elucidate the spectrum of factors associated with facial dermatitis by analyzing data of patients patch tested in the Information Network of Departments of Dermatology (IVDK) between 1995 and 2007. In 18,572 patients the main anatomical site of dermatitis was the face. Among these, the proportion of females and of patients with past or present atopic eczema was increased, while probable occupational causation was less common than in the overall group. Cosmetic allergens, as well as nickel, were significantly more common in women than men, including fragrance mix (10.8% vs. 8.3%), p-phenylenediamine (4.0% vs. 2.8%), lanolin alcohols (3.0% vs. 2.2%), Lyral(TM) (3.1% vs. 2.0%) and bufexamac (1.8% vs. 1.1%). In comparison, only epoxy resin contact allergy was diagnosed significantly more often in men than women: In patients with airborne contact dermatitis, over-represented allergens included sesquiterpene lactone mix, compositae mix, epoxy resin, (chloro-) methylisothiazolinone and oil of turpentine. In the clinical approach to patients with facial dermatitis, occupational airborne causation should be considered in addition to non-occupational (e.g., cosmetic) allergen exposure.

Fragrance ingredient labelling in products on sale in the U.K

BACKGROUND

The seventh amendment of the European Union (EU) Cosmetics Directive (March 2005) and the Detergents Regulations of the EU (October 2005) are now legal requirements in Europe. Cosmetic products and detergents must be labelled for 26 individual named fragrances, when present at concentrations of > 10 parts per million (p.p.m.) in leave-on products and > 100 p.p.m. in rinse-off products.

OBJECTIVES

To make an assessment of the exposure pattern to fragrance of the U.K. consumer and to determine the frequency with which the constituent fragrances of fragrance mix I (FM I) and fragrance mix II (FM II) are included in products currently sold in the U.K.

METHODS

A study of perfumed cosmetic and household products available on the shelves of U.K. retailers was carried out in January 2006. Products were included if 'parfum' or 'aroma' was listed among the ingredients. Three hundred products were surveyed and any of the 26 listed fragrances named on the label were recorded.

RESULTS

The top six most frequently labelled fragrances were linalool (190; 63%), limonene (189; 63%), citronellol (145; 48%), geraniol (126; 42%), butyl phenyl methyl propional (Lilial(trade mark)) (126; 42%) and hexyl cinnamal (125; (42%). One of these, geraniol, is present in FM I and two others, citronellol and hexyl cinnamal, in FM II, thus tested as part of the British Standard patch test series. The frequencies of other constituents of FM I were as follows: eugenol, 80 (27%); hydroxycitronellal, 52 (17%); isoeugenol, 27 (9%); cinnamic alcohol, 25 (8%); amyl cinnamal, 22 (7%); cinnamal, 17 (6%); Evernia prunastri (oak moss absolute), 13 (4%). The other constituents of FM II occurred as follows: coumarin, 90 (30%); hydroxyisohexyl-3-cyclohexene carboxaldehyde (Lyral(trade mark)), 88 (29%); citral, 74 (25%); farnesol, 23 (8%). Linalool (n = 46; 66%) was the most frequently found fragrance in 70 personal care products (soap, shampoo, shower gel). Linalool (n = 47; 80%) and limonene (n = 45; 76%) were the most frequent in 59 products for men (e.g. aftershave). Limonene (n = 29; 51%) predominated in 57 household products (washing-up liquid, detergent). Limonene (n = 43; 98%) and linalool (n = 42; 95%) were the most frequent fragrances in 44 perfumes for women. Alpha-isomethyl ionone (n = 28; 72%) was the most frequent in 39 cosmetics (foundation, lipstick, etc). Citronellol predominated (n = 15; 88%) in 17 deodorants and limonene (n = 9; 64%) was the commonest in 14 dental products (toothpaste and mouthwash). Thirty-four products (11%) contained none of the listed fragrances but were labelled as containing 'parfum' or 'aroma'.

CONCLUSIONS

There is ongoing consumer exposure to the most frequent sensitizers in FM I: E. prunastri, isoeugenol and the cinnamon fragrances cinnamal and cinnamic alcohol. Hydroxyisohexyl-3-cyclohexene carboxaldehyde (Lyral(trade mark)) is present at significant concentrations in almost one-third of products. Linalool and limonene, fragrance terpenes which are significant allergens in their oxidized state, are the most frequent fragrances encountered by individuals living in the U.K. The current exposure pattern of the U.K. consumer suggests that we should add oxidized limonene and oxidized linalool to the test series for patients suspected to have fragrance allergy.

The skin sensitization potential of resorcinol: experience with the local lymph node assay

Resorcinol is a simple aromatic chemical (1,3-benzenediol) that has found widespread use, particularly as a coupler in hair dyes. Clinical experience clearly shows that resorcinol is a (albeit uncommon) skin sensitizer. By contrast, predictive methods, both animal and human, have previously failed to identify resorcinol as such. Here, we describe the outcome of a recent local lymph node assay performed in accordance with Organisation for Economic Co-operation and Development guideline 429, which correctly identified resorcinol as a skin sensitizer. Clear evidence of a dose response was apparent, and an EC3 value of approximately 6% was calculated. This suggests that the skin-sensitizing potency of resorcinol is approximately 2 orders of magnitude lower than that of p-phenylenediamine but similar to that of hexyl cinnamic aldehyde. These data show the importance of adherence to test guidelines and aligns the clinical experience with resorcinol with that obtained in predictive animal methods.