Contact allergy to oxidized d-limonene among dermatitis patients.

d-Limonene, obtained as a by-product from the citrus juice industry, was introduced on the market as a more environmentally friendly defatting and cleaning agent than the traditionally used organic solvents. Autoxidation of d-limonene readily occurs to give a variety of oxygenated monocyclic terpenes that are strong contact allergens. The aim of the present study was to investigate the prevalence of contact allergy to air exposed d-limonene among dermatitis patients. A fraction consisting of d-limonene hydroperoxides was also tested. Screening with oxidized d-limonene will detect cases of allergic contact dermatitis. Additional cases were detected when testing with the fraction of limonene hydroperoxides. The proportion of positive patch test reactions to oxidized d-limonene was comparable to that seen for several of the allergens within the standard series. An increased use of d-limonene containing allergenic oxidation products in industry where high concentrations are used, as well as in domestic exposure, might result in contact sensitization and dermatitis. Patients reacting to d-limonene often reacted to fragrance mix, balsam of Peru and colophony in the standard series.

Corticosteroid contact allergy: an EECDRG multicentre study.

This article describes the results of an EECDRG multicentre study on contact allergy to corticosteroids. A total of 7238 patients were investigated: 6238 in 13 centres in the course of 1993, and 1000 patients in 1 centre in 1993 and 1994. The 5 corticosteroids tested were budesonide 0.1% pet., betamethasone-17-valerate 1% pet., clobetasol-17-propionate 1% pet., hydrocortisone-17-butyrate 1% eth., and tixocortol-21-pivalate 1% pet.; 189 (2.6%) gave a positive patchtest reaction (+, ++, + + +) to at least 1 of the corticosteroids. The data regarding the corticosteroid-sensitive patients, as well as the patchtest results, were recorded on a standardized form.

Sensitization studies with mometasone furoate, tixocortol pivalate, and budesonide in the guinea pig.

Mometasone furoate is a new corticosteroid, synthesized to have an improved ratio of anti-inflammatory potential to adverse effects. The guinea pig maximization test was used to determine the sensitizing capacity of mometasone furoate, and also to investigate cross-reaction patterns in animals sensitized to tixocortol pivalate and budesonide, respectively. Tixocortol pivalate was shown to be a sensitizer in the guinea pig, but cross-reactions to other tested corticosteroids were not observed. Furthermore, no sensitizing capacity could be demonstrated for budesonide or mometasone furoate.

Patch testing with fragrances: results of a multicenter study of the European Environmental and Contact Dermatitis Research Group with 48 frequently used constituents of perfumes.

The objective of this study was to determine the frequency of reactivity to a series of commonly used fragrances in dermatological patients. A total of 48 fragrances (FF) were chosen, based on the publication of Fenn in 1989 in which the top 25 constituents of 3 types (1. perfumes, 2. household products, 3. soaps) of 400 commercial products on the US market had been determined. In a pilot study on a total of 1069 patients in 11 centres, the appropriate test concentration and vehicle were examined. For most fragrances, 1% and 5% were chosen, and petrolatum proved to be the best vehicle in comparison to isopropyl myristate and diethyl phthalate. In the main study, a set of 5 to 10 fragrances at 2 concentrations was patch tested in each centre on a minimum of 100 consecutive patients seen in the patch test clinic. These patients were also patch tested to a standard series with the 8% fragrance mix (FM) and its 8 constituents. In patients with a positive reaction to any of the 48 FF, a careful history with regard to past or present reactions to perfumed products was taken. A total of 1323 patients were tested in 11 centres. The 8% FM was positive in 89 patients (8.3% of 1072 patients). Allergic reactions to the constituents were most frequent to oak moss (24), isoeugenol (20), eugenol (13), cinnamic aldehyde (10) and geraniol (8). Reactions read as allergic on day 3/4 were observed only 10X to 7 materials of the new series (Iso E Super (2), Lyral (3), Cyclacet (1), DMBCA (1), Vertofix (1), citronellol (1) and amyl salicylate (1)). The remaining 41 fragrances were negative. 28 irritant or doubtful reactions on day 3/4 were observed to a total of 19 FF materials (more than 1 reaction: 5% citronellol (2), 1% amyl salicylate (2), 1% isononyl acetate (3), 0.1% musk xylol (2), 1% citral (2), and 1% ionone beta (2)). Clinical relevance of positive reactions to any of the FF series was not proved in a single case. This included the 4 reactions in patients who were negative to the 8% FM. In conclusion, the top 25 fragrances commonly found in various products caused few reactions in dermatological patients and these few appeared to be clinically irrelevant, with the possible exception of Lyral. However, this data should be interpreted in the light of the relatively small number of patients tested (only 100 in most centres).

Contact allergy to imidazoles used as antimycotic agents.

The present article reviews the literature (up to 1994) on contact sensitivity to imidazoles and presents the results obtained from 15 patients observed at the Contact Allergy Unit in Leuven. The frequency as well as the cross-reaction patterns described are analyzed. Although allergic contact reactions may have been missed in the past (mainly because of problems with the correct choice of vehicle for patch testing), they seem to be relatively infrequent in view of their widespread use. The imidazole derivatives most frequently reported to be allergens are miconazole, econazole, tioconazole, and isoconazole. As far as cross-reactivity is concerned, statistically significant associations were found in the patient data between miconazole, econazole, and isoconazole; between sulconazole, miconazole, and econazole; and also between isoconazole and tioconazole. Patients sensitive to phenylethyl imidazoles (except ketoconazole) needing antimycotic therapy should be advised to use ketoconazole, clotrimazole, bifonazole, or, perhaps, the new flutrimazole. Clearly, non-imidazole antifungals can also be used.

Sensitisation to corticosteroids. Consequences for anti-inflammatory therapy.

The frequency with which sensitisation to corticosteroids occurs is under-recognised, and depends on factors such as the type and amount of corticosteroid used, the awareness of the need to test for corticosteroid sensitivity and the methods used to do so. Topically applied corticosteroids, in particular, but also inhalation and systemic corticosteroids may cause allergic reactions. The clinical picture as well as the patch test reactions can be deceptive. Moreover, concomitant and cross-reactions are common.

Contact allergy to allyl glycidyl ether present as an impurity in 3-glycidyloxypropyltrimethoxysilane, a fixing additive in silicone and polyurethane resins.

We present a 43-year-old man who worked in the plastics industry and who suffered from an occupational dermatitis on the hands and forearms. He was found to be allergic to an epoxy silane compound that was contaminated with allyl glycidyl ether, a reactive epoxy diluent. HPLC analysis and patch testing indicated that this impurity was probably the only sensitizer. Moreover, the gloves used provided absolutely no protection, as the inner side also generated strong positive reactions.

The influence of patch tests with clobetasol propionate on adjacent patch test reactions.

Contact allergy to corticosteroids now seems frequent among patients being patch tested. As corticosteroids are intrinsically anti-inflammatory, we investigated whether patch tests with a potent corticosteroid might suppress simultaneous adjacent patch test reactions to another allergen. Nickel-sensitive subjects were patch tested with an aqueous dilution series of nickel in duplicate, adjacent to patch tests with clobetasol propionate 1% in ethanol and with ethanol, respectively. Statistical evaluation of the results obtained in 2 different centers, using their own patch test techniques, did not reveal any suppression of the positive nickel patch test reactions.