A. Dooms-Goossens

Identification of cross‐reaction patterns in allergic contact dermatitis from topical corticosteroids

Contact allergy to topical corticosteroids occurs more frequently than previously supposed. Cross‐allergic phenomena are common. On the basis of a review of the literature and our own patch test data on 15 patients, we conclude that positive patchtests to corticosteroids occur approximately six to seven times more frequently in well‐defined groups of structurally‐related substances than between corticosteroids of different groups. An analogous substitution pattern on the steroid D‐ring or the carbon side chain (C20, C21) seems to have a significant influence on the association of positive patchtest results. This is not the case for other structural variables, such as the presence of a double bond in the steroid A‐ring or fluoride substitutions on the B‐ring. The effect of other factors such as concomitant sensitization and steroid metabolism in the skin on the development of a corticosteroid polyallergy are analysed, and the specificity and sensitivity of cross‐allergy phenomena are evaluated. These are important in the selection of a topical steroid in the future treatment of a corticosteroid sensitive patient.

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 fragrances in dermatological patients. A total of 48 fragrances (FF) were chosen, based on the publication of Fenn in 1989 in which the lop 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 10 × to 7 materials of the new series (Iso L: 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 exeption of Lyral®. However, this data should be interpreted in the light of the relatively small number of patients tested (only 100 in most centres).

Reduced frequency of nickel allergy upon oral nickel contact at an early age.

From animal studies we know that oral administration of T‐dcpcndcnt antigens before sensitization effectively induces systemic immune unresponsiveness. Such ‘oral tolerance’ is persistent, dose‐dependent, antigen‐specific and presumably T suppressor cell‐mediated. Oral tolerance induction could be an effective way to prevent undesired T cell‐mediated immune functions, such as playing a role in allograft reaction, autoimmune and allergic diseases. In the present study allergic contact hypersensitivity (ACH) to nickel, currently presenting the most frequent contact allergy in man, was chosen to establish the feasibility of oral prevention of undesired T cell‐mediated immunity in man. Potentially tolerizing (oral nickel contacts via orthodontic braces) as well as sensitizing (ear piercing) events were studied retrospectively in 2176 patients attending nine European patch test clinics. Patients were interviewed by means of a confidential questionnaire. The results show that ear piercing strongly favoured development of nickel ACH. More importantly, patients having had oral contacts with nickel‐releasing appliances (dental braces) at an early age, but only if prior to ear piercing, showed a reduced frequency of nickel hypersensitivity. Frequencies of other hypersensitivities, in particular to fragrance, were not affected. These results support our view that induction of specific systemic immunologic tolerance by timely oral administration of antigens is feasible in man.

Protein contact dermatitis: myth or reality?

Protein contact dermatitis is a dermatosis which usually presents as a chronic eczema with episodic acute exacerbations a few minutes after contact with the offending allergen. Patch tests with the responsible allergen are usually negative, and the diagnosis can only be made by means of scratch or prick tests with the allergen. Sometimes, specific IgE antibodies can be detected in the blood. As there is considerable confusion about this entity, we have reviewed the cases reported in the literature.

The chemistry of contact allergy: why is a molecule allergenic?

This review concentrates on some specific aspects of the chemistry of allergic contact dermatitis. The way low molecular weight chemicals react with skin proteins to form complete antigens will be discussed and the development of molecular modelling techniques to analyse molecular recognition presented. Subsequently, how knowledge of the chemical structure can be used to estimate the allergenic activity of a molecule will be considered. This aspect includes work with qualitative and quantitative structure‐activity relationships (SAR) in the field of contact allergy.

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 UAT 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.

Contact dermatitis caused by airborne agents: A review and case reports

A general review is given of airborne-induced contact dermatoses, particularly of the irritant and allergenic types. Because the reports in the literature often omit the term airborne, 12 volumes of Contact Dermatitis (January 1975-July 1985) were screened, and the cases cited were classified in function of the anamnesis, lesion locations, causative irritants and allergens, and other factors. The present article also discusses differential diagnoses, in particular with regard to contact dermatitis of the face, ears, and neck. Finally, seven case reports of occupational and nonoccupational contact dermatitis problems caused by airborne agents are presented. In some of the cases the allergens have not been mentioned in published literature previously.

Allergic reactions to a hairdressers’series: results from 9 European centres

To obtain data on the frequency of sensitization among European hairdressers, the patch test results from 9 centres were evaluated. 8 allergens recommended by the ICDRG and EECDRG in the hairdressing series and PPD from the standard series were used to patch test 809 hairdressers and 104 clients suspected of contact sensitization. Among hairdressers, the mean frequencies of sensitization ranked as follows: GMT 19%, PPD 15%, APS 8%, PTD 8%, ONPPD 4%, and PADH 4%. In contrast to GMT in acid permanent waves, the frequency of sensitization to AMT in alkaline permanent waves was only 4%. Frequencies of sensitization to pyrogallol and resorcinol were 0.8% and 0.6%, respectively. The frequencies of sensitization showed marked regional variations, particularly that to GMT, which was highest in Germany (51%), followed by Spain (22%) and London (19%). Clients of hairdressers showed a similar rank order of sensitization frequency, with the exception of APS, which was completely negative in this (small) 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 tixoeortol‐21‐pivalate 1%., pet.; 189 (2.6%) gave a positive patehtest reaction (+, ++, +++)to at least 1 of the corticosieroids. The data regarding the corticosteroid‐sensitive patients, as well as the patchtest results, were recorded on a standardized form.

Patch testing with the "sesquiterpene lactone mix": a marker for contact allergy to Compositae and other sesquiterpene-lactone-containing plants. A multicentre study of the EECDRG

6278 patients were patch tested with a sesquiterpene lactone mix (SL‐mix) in 10 European clinics. 4011 patients were tested only with 0.1% SL‐mix. 63 (approximately 1.5%) of whom were positive, with 26 (41%) of these cases being considered clinically relevant. There were no cases of active sensitization occurred though 5 eases of irritation were reported. 22 irritant reactions and 22 cases of active sensitization occurred when testing also with 1% and 0.33% concentrations of SL‐mix. SL‐mix 0.1% pet is shown to be an important patch test and many relevant sensitizations will be missed without routine screening with such a mix. Most patients with SL‐mix sensitivity presented with hand and/or face dermatitis, apparent photodermatitis or more generalised eczema.