An epidemic of occupational contact dermatitis from an immersion oil for microscopy in laboratory personnel

Since November 1997, 14 successive cases of occupational contact dermatitis were observed in 13 laboratory technicians and 1 physician, working in a genetics laboratory in Leuven (Belgium) in 3 laboratories of bacteriology in Strasbourg, Montbeliard and Angers, and in the laboratory of hematology in Bordeaux (France). The dermatitis, located on the hands, forearms and face, relapsed after each exposure to an immersion oil for microscopy. Patch tests performed in 10 patients were positive to epoxy resin (ER) in the European standard series (10/10 patients) and to newly formulated Leica immersion oil (7/7), 1 patient testing negatively with the former oil. A breakdown performed in 2 patients with the oil's ingredients confirmed sensitization to liquid modified ER components, contained at >80% concentration in the oil. The presence of DGEBA was demonstrated by HPLC analysis at a +/-30% rate. Although the safety data sheet indicated a revision of the formula, nobody was alerted to the risk of sensitization and the need for skin protection. ERs, as a source of occupational allergy, can provoke epidemics of contact dermatitis in industry. This report of epidemic contact dermatitis from ERs, used for their optical properties in an immersion oil for microscopy, emphasizes the need for perpetual vigilance in occupational medicine and the usefulness of multicentre contacts in dermato-allergology.     

Sensitization to cockroach allergens evaluated by skin tests in children with atopic dermatitis

INTRODUCTION: Cockroach and house dust mites (Dermatophagoides pteronyssinus, Dp and farinae, Df) are the most often implicated aeroallergens in severe asthma, hay fever and conjunctivitis. Cockroach allergy is still unknown in atopic dermatitis.PATIENTS AND METHOD: 146 children with atopic dermatitis-aged 6 months to 15 years- have been patch tested with the European standard series and some aeroallergens. We have studied the sensitisation to cockroach allergens and compared to Dp and Df.RESULTS: 113 children reacted positively at least to one of the 3 aeroallergens (77 p. 100), 61 children had a positive reaction to cockroach (42 p. 100) and 29 simultaneously to the 3 allergens.DISCUSSION: Delayed hypersensitivity to house dust mites in young children with atopic dermatitis suggests early epicutaneous sensitization due to an altered epidermal barrier. For us, cockroach could also be implicated in some flare-ups of atopic dermatitis. Eviction of cockroach and house dust mite should be proposed for children with a positive patch test to cockroach.     

FS01.3Disperse (yes), orange (yes), 3 (no): what do we test in textile dye dermatitis?

Introduction:  Patients sensitized to para‐phenylenediamine (PPD) have a high degree of patch test reactivity to Disperse Orange 3 (DO3), and a lesser one to Disperse Red 1 and Red 17. Two successive patients positive to PPD, Disperse Red 1 and 17, negative to DO3 were real eye‐openers for our considerations about purity of our current allergen DO3.
Materials and methods:  We realized comparative thin‐layer chromatography (TLC), with DO3 from Chemotechnique®(DO3‐Chem) and Trolab®(both extracted from petrolatum), and "pure" DO3 from two chemical providers. TLC clearly indicated that DO3‐Chem was not DO3. HPLC analysis with pure DO3 from Chemotechnique® and comparison of structures by NMR with samples of DO3, revealed that DO3‐Chem was Disperse Orange 31 (DO31). In addition, signals through the GERDA network allowed the collection of test materials and observations. Among other members, only 2 used DO3‐Chem (from 2 different batches) that was DO31 too, according to TLC Results: According to their data, they observed no or a lower reactivity to DO3 than expected (4 patients DO3‐Chem + among 23 PPD+ e.g.). Finally, the error was proved to be due to the provider of the dye to Chemotechnique®, who likely deleted the 1 of Disperse Orange 31 on his packaging.
Discussion:  Chemical structure of DO31 indicates a possible in vivo hydrolysis into nitroaniline and a second compound, a substituted PPD derivative that clearly does not frequently react in PPD positive patients. Like drugs, patch tests are submitted to post‐commercialization controls. In addition to allergens providers who should enhance their quality controls, dermato‐allergologists have to be vigilant, and must active networks when they observe a rare bird.     

Routine patch testing with the sesquiterpene lactone mix in Europe: a 2-year experience. A multicentre study of the EECDRG

To test the screening value of the sesquiterpene lactone (SL) mix in Europe today and describe epidemiological and clinical features of Compositae-sensitive patients, the SL mix 0.1% pet. was included in the standard patch test series in 11 European clinics. 10,695 patients were tested, and 106 (1%) had positive reactions, 74% of which were of current or old relevance. The prevalence of positive reactions varied between 0.1 and 2.7% in different centres. The median age of the 66 females was 51.5 years, and 55.2 in the 40 males. The 20 occupationally sensitized had a higher % of males and a median age of 43 years, whereas 7 UV-sensitive patients had a median age of 72 years. Garden plants were the major suspected sensitizers and the clinical patterns were partly, in accordance with plant dermatoses in general, involving hands, forearms and face, and partly widespread eczema in a large proportion of the patients. More than 1/3 were positive to perfume and/or colophony, possibly reflecting cross-reactivity. With only 1 case of active sensitization and no irritant reactions, the SL mix is a safe allergen and the overall prevalence of positive reactions supports its continued use in the standard patch test series.     

Contact dermatitis

In recent years, there has been a dramatic rise in our understanding of contact dermatitis. This paper is a review of our knowledge of the mechanisms involved in contact dermatitis and related phenomena, the investigation of these events and the emergence of significant new allergens during the last 5 years.     

Contact allergy to aeroallergens in children with atopic dermatitis: comparison with allergic contact dermatitis

Immediate and delayed cutaneous hypersensitivity are believed to be implicated in the physiopathology atopic dermatitis (AD). The purpose of this study was to evaluate Type I and Type IV allergy to aeroallergens in children with AD. 59 children (mean age 5.2 years), presenting with AD according to Hanifin and Rajka's criteria, were skin tested (patch and corresponding prick tests) with common environmental aeroallergens and a restricted panel of the European standard series over a 1-year period. History and clinical data were carefully recorded using a standardized evaluation sheet: total and specific IgE serum levels were evaluated 17 of 59 patients (28.8%) had at least 1 positive patch test, 32 of 59 patients (54.2%) had at least 1 positive prick test. Corresponding patch and prick tests were observed in 8 out of 17 patients. 5 children with positive patch tests had negative prick tests. Irritant pustular reactions (2/59, i.e. 3%), "angry back" reactions (6/59, i.e. 10%) and doubtful reactions (3/59, i.e. 5%) were excluded from the positive group. Positive patch tests observed included, in decreasing order: D. pteronyssinus and D. farinæ (26.8%) garden trees (12.2%), plantain (9.8%), timothy grass, mugwort and damp area trees (4.9% each), and orchard grass (2.44%). 6 children with positive aeroallergen patch tests and 11 children with negative aeroallergen patch tests had at least 1 positive patch test to standard allergens. All children with an irritant reaction to aeroallergens had no reaction to standard patch tests. The relevance of aeroallergens in upgrading the severity of AD lesions has still to be explored by challenge studies and by long-term follow-up.