Allergic contact dermatitis from pharmaceutical grade BHA in Timodine, with no patch test reaction to analytical grade BHA

Allergic and immunologic reactions to food additives

For centuries, food additives have been used for flavouring, colouring and extension of the useful shelf life of food, as well as the promotion of food safety. During the last 20 years, the studies implicating the additives contained in foods and medicine as a causative factor of allergic reactions have been proliferated considerably. In this review, we aimed to overview all of the food additives which were approved to consume in EU and find out how common and serious allergic reactions come into existence following the consuming of food additives.

An α,β-unsaturated oxime identified as a strong contact allergen

The aim of this study was to examine the possible skin sensitizing effect of oximes, employing an alpha,beta-unsaturated oxime as the model compound. Oximes are not frequently used as biologically active compounds. However, they have been shown to possess both anti-inflammatory and anti-allergic activities. Furthermore, in a recent study, a number of oximes and oxime-ethers of hydroxylated benzaldehydes and acetophenones were found to be powerful antioxidants suggested to be used in consumer products such as cosmetics and food. Although there are only few reports on the sensitizing effect of oximes, their ability to be hydrolyzed to the corresponding ketones or aldehydes makes them potential contact allergens. The oxime investigated in this study was demonstrated to be a strong contact allergen in both mice and guinea pigs, capable of sensitize the control animals after only one dermal exposure. In order to elucidate the mechanisms for the formation of the complete antigen, a variety of analogues with different reactivity were tested. The results indicate that alpha,beta-unsaturated oximes can react with proteins via several different pathways. Most likely, a metabolic transformation is involved. Due to the strong allergenic effect of the oxime investigated, we strongly advise against the use of such oximes in consumer products until a better understanding of their interactions with biological macromolecules has been obtained.

Cosmetic allergy: incidence, diagnosis, and management

A recent epidemiologic survey in the UK revealed that 23% of women and 13.8% of men experience some sort of adverse reaction to a personal care product over the course of a year. Although most of these reactions may be due to subjective sensory irritation, various studies reveal that up to 10% of dermatologic patients who are patch tested are allergic to cosmetic products or their constituent ingredients. Causative products include deodorants and perfumes, skin care products, hair care products, and nail cosmetics. Allergic contact dermatitis mainly results from fragrance chemicals and preservatives. Recent work has suggested that additional fragrance chemicals may need to be tested in order to identify those patients 'missed' by the current fragrance mix; in particular, hydroxy-isohexyl-3-cyclohexene carboxaldehyde (HMPPC Lyral) has been singled out as an important sensitizing agent. The increased usage of natural fragrances and botanic extracts can also cause problems in their own right or through co-reactivity. The preservative methyldibromo glutaronitrile has also been recognized as an increasingly important sensitizer in Europe, which has led to the recent recommendation that it should be prohibited from 'leave-on' products until information on 'safe' consumer levels becomes available. Other emerging allergens include UV filters, tosylamide/formaldehyde resin, and nail acrylates. The diagnosis of cosmetic allergy should be confirmed with patch testing, including testing of 'whole' products, when necessary, and repeat open application tests can be used to confirm the relevance of reactions in cases of doubt.