Intervention study to evaluate the importance of information given to patients with contact allergy: a randomized, investigator-blinded clinical trial.

BACKGROUND: In contact dermatitis, it is crucial to understand and remember the outcome of patch testing. Unfortunately, many patients do not remember the results of their patch tests. OBJECTIVES: Our aim was to evaluate the effects of an intervention programme in which extensive information on specific contact allergy was provided, in individuals with positive patch test reactions. METHODS: The study was designed as a randomized, investigator-blinded clinical trial. Participants with positive test reactions were randomized into two groups that received either standard information according to clinical routine or standard information and a reminder letter. Knowledge of contact allergies was evaluated using questionnaires 12 months after inclusion. RESULTS: There were 184 adults included in the trial and the response rate at 1-year follow-up was 78% (143 of 184). Sixty-five per cent (45 of 69) in the intervention group and 54% (40 of 74) in the control group reported the correct name of the allergen (P = 0·23). Participants with several - as opposed to few - positive patch test reactions had difficulty in remembering the correct names of the allergens (P = 0·001). Moreover, the type of allergy had an influence on their ability to remember the name of the allergen correctly and their ability to make changes in lifestyle. CONCLUSIONS: The intervention performed did not significantly affect the participants' ability to remember their contact allergy. To achieve better knowledge and changes in lifestyle, efforts to inform should concentrate on individuals with several positive patch test reactions, those with particular allergens, individuals over 60 years of age, and - concerning changes in lifestyle - males.

Wet work exposure and hand eczema among healthcare workers: a cross-sectional study.

BACKGROUND: Hand eczema is more common in healthcare workers than in the general population. Hands are subject to changing occupational exposures as a result of mandatory hygiene regulations for healthcare workers. OBJECTIVES: To describe exposure to hygiene procedures and investigate the associations between occupational hand washing, use of nonsterile gloves and hand disinfectant, and self-reported hand eczema. METHODS: This was a cross-sectional study; an electronic questionnaire was distributed to 28 762 hospital employees in southern Sweden. Nurses, assistant nurses or physicians constituted the group of healthcare workers analysed. Adjustments were made for sex, age, wet work at home, lifestyle factors and atopic dermatitis. RESULTS: In total, 12 288 (43%) responded, including 9051 healthcare workers. In this group the 1-year prevalence of self-reported hand eczema was 21%. On a daily basis, 30% reported hand washing with soap > 20 times at work, 45% used hand disinfectants > 50 times and 54% wore nonsterile gloves for > 2 h. After adjustment for confounding factors, a dose-dependent association with self-reported hand eczema was found for the daily number of hand washes with soap at work and time working with disposable gloves but not for alcoholic disinfectant use. Hand washing outside work was not associated with self-reported hand eczema in the adjusted multivariate analysis. CONCLUSIONS: In this study, we found a higher 1-year prevalence of self-reported hand eczema among Swedish healthcare workers than reported in the general population. Hand washing with soap and use of disposable gloves were associated with the occurrence of self-reported hand eczema in a dose-dependent way. Use of hand disinfectant was not associated with self-reported hand eczema.

Extraction of haptens from solid products and their delivery to the skin, exemplified by dithiocarbamates from rubber gloves.

Allergic contact dermatitis is often caused by solid products such as rubber gloves. Patch testing with the product as is often gives negative results. Extraction of the haptens into an organic solvent is commonly performed to achieve a more correct investigation. The technique used for extraction of haptens from solid materials is only sporadically described. In this study, we investigated and optimized the yields of dithiocarbamates obtained by extraction from rubber gloves. The influence of solvent, extraction time and the procedures for extraction are evaluated. The delivery of zinc dibutyldithiocarbamate from the patch test preparation to the skin is determined.

HPLC analysis of alkyl thioureas in an orthopaedic brace and patch testing with pure ethylbutylthiourea.

Ethylbutylthiourea (EBTU) is an accelerator used in the production of chloroprene (neoprene) rubber. EBTU occurs in a mixture with diethylthiourea (DETU) and dibutylthiourea (DBTU) in the accelerator. An analytical method originally developed for analysis of zinc dithiocarbamates in rubber has been used to analyse EBTU, DETU and DBTU in a knee brace responsible for an allergic contact dermatitis in a gardener suffering from arthrosis. EBTU was isolated and gave positive reactions when tested as a pure compound. The test reaction was accompanied by positive reactions to DETU and DBTU.

Stability of thiuram disulfides in patch test preparations and formation of asymmetric disulfides.

The thiuram mix used in patch testing originally contains 4 compounds. However, chemical analysis of the test preparation revealed that several new compounds are spontaneously formed during storage. The structures of these compounds have been determined and the rate of their formation has been studied in buffer solution at pH 7.4. After a few hours, a large amount of mixed disulfides are formed in solutions originally containing only symmetric disulfides. The impact on the test result of the formation of asymmetric disulfides has been investigated by testing on thiuram-sensitive volunteers with different preparations of mixed thiuram disulfides. In our study, the formation of new asymmetric thiuram disulfides from the original symmetric thiuram disulfides in the test preparation had no influence on the result of the patch testing. However, as the chemical analysis showed that the mix composition changes during the period when the preparations are used, and differs between suppliers, the question is raised as to whether it is acceptable to use test preparations with a composition that is different from that labelled on the protocol.

Activation and cross-reactivity pattern of a new allergen in adhesive plaster.

N,N'-disalicylidene-1,2-diaminopropane is a copper inhibitor present in some adhesive plasters, rubber products and gasoline. Upon contact with water it is hydrolyzed to salicylaldehyde and 1,2-diaminopropane. All patients in this study showed positive patch-test reactions to N,N'-disalicylidene-1,2-diaminopropane, and also to 1,2-diaminopropane and ethylenediamine. None reacted to salicylaldehyde. Patch testing with different N,N'-disalicylidene-derivatives showed localization of the amino groups in positions 1 and 2 to be a prerequisite of cross-reactivity to 1,2-diaminopropane and ethylenediamine. An extraction procedure and a high-performance liquid chromatography (HPLC) method for the analysis of adhesive plasters is described. Studies of the hydrolysis of the copper inhibitor at physiological pH showed rapid formation of 1,2-diaminopropane under biomimetic conditions.

Concomitant contact dermatitis due to textile dyes and to colour film developers can be explained by the formation of the same hapten.

p-phenylenediamine derivatives are widely used in industry and in cosmetics, and several of them are well-known sensitizers. One group of allergenic p-phenylenediamine derivatives are used as colour film developers. Cross-reactivity between the colour film developers has been reported. In this paper, an occupational facial dermatitis due to colour film developers is described. The patient reacted to colour film developers (CD-1, CD-2, CD-3, and CD-4), but not to other p-phenylenediamine derivatives tested. He also showed allergic reactions to Disperse Blue 106 and Disperse Blue 124 and to Disperse Red 17, but not to Disperse Orange 3. The activation of the colour film developers by oxidation at physiological pH was analysed with chemical methods, and the mechanism responsible for the concomitant reactivities to the colour film developers and the disperse dyes at a molecular level is discussed.

Minor components with smooth muscle relaxing properties from scented myrrh (Commiphora guidotti).

All sesquiterpenes present in a sample of scented myrrh were isolated and characterised. Seven compounds, with cadinane, guaiane, oplopane, and eudesmane skeletons, were obtained, of which two are new and two are reported from a natural source for the first time. The major component, T-cadinol, has previously been shown to possess smooth muscle-relaxing properties, and the major purpose of the investigation was to compare the effects of the minor and more polar sesquiterpenes with that of T-cadinol in the rat aorta. Like T-cadinol, the minor sesquiterpenes are more efficient in reducing K(+)-induced contractions than those induced by the alpha-adrenoceptor agonist phenylephrine, however, they were all less potent than T-cadinol.

Extraction of mercaptobenzothiazole compounds from rubber products.

At evaluation of contact dermatitis caused by solid material, patch testing is usually performed with the material as such and with extracts of it. In this study, optimization of the extraction technique monitored by quantitative HPLC analysis of the extracted haptens is described for mercaptobenzothiazole derivatives. Several solvents with different properties are included. Acetone has traditionally been a solvent widely used for the extraction of organic haptens from solid products. However, acetone and other ketones are not inert solvents. The rubber accelerators 2-(4-morpholinyl mercapto) benzothiazole (MMBT) and N-cyclohexyl-2-benzothiazyl sulfenamide (CBS) react with acetone, yielding 2 new compounds, which were isolated and characterised by NMR and MS. For the extraction of solid rubber products, methyl tert-butyl ether (MTBE) was found to be a more suitable solvent which is unreactive to most common haptens.

Furanocoumarins with affinity to brain benzodiazepine receptors in vitro.

Eight furanocoumarins were isolated from a methanol extract of dried roots of Angelica dahurica. One of these, phellopterin, strongly (IC50 = 0.36 microM) inhibits the binding of [3H]diazepam to central nervous system benzodiazepine receptors in vitro, while the others, despite their structural similarities with phellopterin, are considerably less active.

Spasmolytic flavonols from Artemisia abrotanum.

Four flavonols with spasmolytic activity have been isolated from a methanol extract of Artemisia abrotanum L. (Asteraceae), as the principles primarily responsible for the smooth muscle relaxing activity of this plant. The flavonols show a dose-dependent relaxing effect on the carbacholine-induced contraction of guinea-pig trachea, the EC50 values for compounds 1-3 are 20-30 mumol/l while compound 4 is less active.

Inhibition of kainic acid binding to glutamate receptors by extracts of Gastrodia.

S-(4-hydroxybenzyl)glutathione was isolated as the major principle responsible for the inhibition of the in vitro binding of kainic acid to brain glutamate receptors by water extracts of the plant Gastrodia elata. The affinity (IC50 value) of the compound is slightly lower compared to glutamate and glutathione.

Inhibition of [methyl-3H]diazepam binding to rat brain membranes in vitro by dinatin and skrofulein.

Two flavones, 4',5,7-trihydroxy-6-methoxy flavone (dinatin) and 4',5-dihydroxy-6, 7-dimethoxy flavone (skrofulein), were extracted from Artemisia herba alba L. Dinatin and skrofulein inhibited the binding of [methyl-3H]diazepam to rat brain membranes in vitro with IC50 of 1.3 and 23 mumol.L-1, respectively. The GABA-ratios (the ratio of IC50 values in the absence/presence of GABA in the binding assay) were 1.1 and 1.2 for dinatin and skrofulein, respectively. Both flavones induced a slight increase in [35S] TBPS binding. The data suggest that the flavones are antagonists or partial agonists of benzodiazepine receptors.