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Notes: 5 patients with allergic contact dermatitis caused by various paints were demonstrated to be sensitive to a cyclohexanone resin (C-R) present in the paints. Sensitization studies in guinea pigs with C-R and cyclohexanone showed one batch of C-R to be a sensitizer.

Notes: To diagnose allergic or irritant contact dermatitis, a clinically relevant contact allergy has to be demonstrated or ruled out, respectively. Although patch testing has been used for 100 years, it remains the method of choice for diagnosing contact allergy. A disadvantage of patch testing is that reading is subjective, based on inspection and palpation of the test area, implying that the assessment is subject to the reader's knowledge and experience. This study was carried out to investigate the accordance in reading patch test reactions between 5 dermatologists. 4 groups, each with 10 patients, participated. Within each group, all 10 were allergic to one and the same sensitizer; nickel, epoxy resin, ethylenediamine, or Kathon CG. The sensitizers were tested in serial dilutions and applied randomly to the back. The tests were read independently by the dermatologists in a blinded fashion. A protocol was used where the dermatologists had to note the presence of the morphological features erythema, infiltration, papules, vesicles, and bullae. In this way, it was possible to allocate the various readings into 4 classification systems, 3 European and one American, although the definition of the various classifications might differ slightly. Based on the readings and classifications, it was possible to calculate the degree of accordance within the 4 systems used. It was also possible to analyze the degree of accordance for the various morphological features. Total accordance for the 5 reading dermatologists for positive and negative test reactions was noted in 36% and 46%, respectively. The 3 European systems require homogenous erythema and infiltration for a reaction to be classified as allergic, while the American system also requires the presence of papules. Therefore, a higher number of allergic reactions (9%) was obtained with the European systems. Between the 4 classification systems, there were statistically significant differences, with the highest number of deviations for the system in which papules had discriminatory significance. When looking at the various morphological features, papules were most difficult to assess, followed by vesicles. Preferably, a classification system should not depend on papules. In conclusion, there was good accordance among the dermatologists in reading patch test reactions, since the 5 dermatologists read 82% of all tests similarly.

Notes: In a double blind experimental study, 20 patients with a contact allergy to gold sodium thiosulphate were challenged intramuscularly with the chemically similar gold sodium thiomalate and with placebo. The most spectacular clinical reaction in the 10 patients given the active agent, was an epidermal and dermal flare up of healed patch-test reactions to the gold salts, as well as a high, but transient, rise in body temperature. Previous intradermal tests were similarly reactivated. In addition, toxicoderma-like rashes were observed in several cases, but a flare up of a previous contact dermatitis site was seen in one patient only. The specificity of the positive provocations was demonstrated.

Notes: Background During the 1980s routine wearing of gloves in dentistry was recommended by health authorities in several countries. However, prolonged glove use is associated with side-effects of irritant and allergic origin. Objectives To investigate the extent of glove use and self-reported glove intolerance reactions among Swedish dentists, and to examine how far IgE-mediated allergy to natural rubber latex (NRL) occurs in subjects who report rapid itching when in contact with protective gloves. Subjects/methods A postal questionnaire was answered by 3083 of 3500 licensed dentists, a response rate of 88%. Of the dentists who reported rapidly occurring itching of the hands from gloves, 131 of 170 attended a clinical examination including a skin prick test (SPT) and a serological examination (RAST) for IgE-mediated allergy. Results Seventy-three per cent of the dentists reported daily glove use of more than 2 h, 48% more than 6 h a day, and 6% reported no use. NRL gloves were used most frequently (P 〈 0·001) and were the main material that elicited symptoms (P 〈 0·001). Female dentists reported more frequent glove use than males, as did young dentists (P 〈 0·001) compared with older ones. Females also preferred vinyl gloves. Glove intolerance reactions were reported by 723 (23%) dentists, [females 28%, males 21% (P 〈 0·001)] and were more common in younger dentists. Of the 417 dentists with reported hand eczema during the previous year, 54% reported glove intolerance, compared with 20% of the dentists without hand eczema (P 〈 0·001). A logistic regression analysis including hand eczema, age, sex and atopy showed that all these factors contributed significantly to the risk of glove intolerance, and that hand eczema was a stronger factor than atopy. In 15 of 131 (11%) dentists examined for reported glove-related itch, latex allergy was verified by SPT and/or RAST. Glove-related conjunctivis, rhinitis and asthma, in contrast to skin symptoms, showed a significant association with IgE-mediated allergy to NRL. Conclusions Swedish dentists show good compliance with the recommendations for routine glove use. Intolerance reactions are frequently reported, especially by dentists with hand eczema, which emphasizes the need for preventive skin care programmes. Glove-related symptoms from mucous membranes showed a higher association with IgE-mediated allergy to NRL than reported itching of the skin, a fact that should be considered when composing screening questionnaires for NRL sensitization

Notes: The frequency of positive reactions to 5-chloro-2-methyl-4-isothiazolin-3-one (MCI/MI) were studied at 22 European cntact dermatitis clinics over a period of 1 year. A total of 4713 patients participated. All the patients were patch tested with nickel sulphate, formaldehyde, paraben-mix, and MCI/MI 19.4% of the patients had positive patch tests to nickel, making this the most common allergen, 3% of the patients reacted to 100 ppm MCI/MI, while 2.6% reacted to formaldchyde and 1.1% to parabens. There was great variation in the frequency of MCI/MI sensitivity among the 22 centres. MCI/MI contact allergy was most common among women and in patients with facial dermatitis, while it was rarely seen in patients with dermatitis on the lower legs. There were no fluctuations in the number of positive patch tests to MCI/MI on a monthly basis when the results from all centres were combined. 117 of the 141 MCI/MI sensitized patients included in the study were retested 88% had positive patch tests when retested. 101 of the MCI/MI-sensitive patients participated in a double -blind, placebo-controlled product use test. This test showed that 31% of the MCI/MI-sensitive patients had a positive reaction to a MCI/MI-preserved product. Only a few patients reacted to a control product. It is concluded that the preservative MCI/MI is an important new contact allergen.

Notes: The preservatives imidazolidinyl urea (IMID, Germall 115) and diazolidinyl urea (DU, Germall II) are commonly used in cosmetic products and are well-known sensitizers. The aim of the present study was to establish the optimal patch test concentration in hydrophilic dried-in vehicle (TRUE Test) for IMID and DU. 181 patients were included in the study. Of these, 150 were patients referred for patch testing, 12 were patients with known allergy to IMID and 19 were patients with known allergy to DU. 76 consecutive patients and the 12 IMID-allergic patients were patch tested with a dilution series IMID (0 to 600 μg/cm2), formaldehyde (180 μg/cm2) and DU (200 μg/cm2). 74 consecutive patients and the 19 DU-allergic patients were patch tested with a dilution series of DU (0 to 600 μg/cm2), formaldehyde (180 μg/cm) and IMID (200 μg/cm2). A positive dose-response relationship was found. The number of doubtful reactions decreased with increasing test concentrations. No late reactions were observed. A patch test concentration in hydrophilic dried-in vehicle (TRUE Test) of 600 μg/cm2 was found to be adequate and safe for both IMID and DU.

Notes: Hand eczema and contact allergy in Swedish dentists were studied in a multidisciplinary project. The aims of the study were to establish diagnoses, to investigate the occurrence of contact allergy, in particular to (meth)acrylates, and to evaluate certain consequences of hand eczema. A postal questionnaire on skin symptoms, atopy and occupational experience was mailed to 3500 dentists aged 〈65 years, and licensed 1965–1995. The response rate was 88%. Among dentists living in 3 major cities, 14.9% (n=191) reported hand eczema during the previous year. They were invited to a clinical examination, including patch testing with a standard and a dental series. 158/191 (83%) dentists attended, and hand eczema diagnosis was confirmed in 149/158 (94%). Irritant contact dermatitis was diagnosed in 67% and allergic contact dermatitis in 28%. On patch testing, 50% presented at least 1 positive reaction. The most frequent allergens were nickel sulfate, fragrance mix, gold sodium thiosulfate and thiuram mix. 7 (5%) had positive reactions to (meth)acrylates, all to 2-hydroxyethyl methacrylate and 6 also to ethyleneglycol dimethacrylate. 38% had consulted a physician, 4% had been on sick-leave and 1% had changed occupational tasks due to hand eczema. No dentist with allergy to acrylates had been on sick-leave or changed occupation. It is concluded that dentistry is a high-risk occupation for hand eczema, and that irritant contact dermatitis is most common. The prevalence of contact allergy to acrylates was below 1% in the population of responding dentists, and in most cases did not have serious medical, social or occupational consequences.