captax and Dermatitis--Allergic-Contact

Patch testing with a baseline series is a common tool employed when the sensitizing agent in contact dermatitis is unclear. However, for Asian countries, there are no locally validated baseline series to utilize in screening.. We completed a retrospective analysis of all patients that had undergone patch testing with the European Baseline series, Shoe Series or Comprehensive International Baseline series, over 7 years from 2012 to 2018 in a tertiary care reference dermatology clinic in Sri Lanka to evaluate the suitability of these investigations to identify causes for contact dermatitis in the local study population.. Out of 438 patients tested, 239 (54.8%) reacted to at least one substance in the series. The Shoe Series was significantly more likely to yield a positive result than the European Baseline Series (70.2% vs 46.9%, p < 0.05). The top three sensitizers identified by all series were nickel sulfate (16%, 70/438), p-phenylenediamine (12.3%, 54/438) and 2-mercaptobenzothiazole or mercapto mix (10.5%, 46/438).. Shoe series has a comparatively high yield in the local population compared to European Baseline series. Since little less than half of the study population did not have any reactivity to any of the allergens tested it is important to develop or modify and validate a locally relevant, more suitable baseline series which is based on the Shoe Series in Sri Lanka. This is further evidence for the continuously changing nature of allergens in the environment and the need to modify existing patch testing standards accordingly.

Topics: Administration, Cutaneous; Adolescent; Adult; Aged; Aged, 80 and over; Allergens; Benzothiazoles; Dermatitis, Allergic Contact; Female; Humans; Male; Middle Aged; Nickel; Patch Tests; Phenylenediamines; Retrospective Studies; Sri Lanka; Tertiary Care Centers; Young Adult

Topics: Aged; Benzothiazoles; Cheilitis; Dermatitis, Allergic Contact; Female; Humans; Patch Tests; Rubber; Toothbrushing

Topics: Adult; Aged; Aldehydes; Allergens; Benzothiazoles; Biostatistics; Cyclohexenes; Dermatitis, Allergic Contact; Ethylene Glycols; Facial Dermatoses; Female; Foot Dermatoses; Hand Dermatoses; Head; Humans; Leg Dermatoses; Machine Learning; Male; Middle Aged; Nitriles; Patch Tests; Perfume; Sulfhydryl Compounds; Torso

Geriatric nurses (GN) have a high risk of occupational contact dermatitis (OCD), with chronic irritant contact dermatitis predominating. However, allergic contact dermatitis is an important issue as well. Little is known whether the relevant occupational allergen spectrum reported in the 1990s, including fragrances, preservatives, rubber chemicals and ingredients of surface disinfectants to be the most common sensitizers in GN, is still valid.. To monitor the current allergen spectrum in GN with OCD and verify the validity of the patch test recommendations (baseline-, preservative-, ointment base-, rubber-, disinfectant, series and fragrances) in GN with suspected OCD given by the German Contact Dermatitis Research Group (DKG).. Retrospective analysis of IVDK data (2005-2014) of 743 female GN with OCD, in comparison to 695 GN without OCD.. GN with OCD reacted significantly more frequently to both fragrance mixes, hydroxyisohexyl 3-cyclohexene carboxaldehyde (HICC), thiuram mix, zinc diethyldithiocarbamate and mercaptobenzothiazole than GN without OCD. Reactions to MDBGN, methylchloroisothiazolinone/methylisothiazolinone and oil of turpentine occurred substantially, but not significantly more frequently among GN with OCD. The latter may be due to former use of a special alcoholic liniment in geriatric care. Among material from the patients' workplaces, tetrazepam was a frequent allergen, due to dust exposure from pill crushing. Furthermore, occupationally used protective gloves, body care products as well as surface disinfectants were often tested positively.. The general allergen spectrum in GN with OCD is unchanged, so the DKG patch test recommendations are still valid. Prevention of occupational sensitization should focus on fragrance-free hygiene and body care products, usage of accelerator-free protective gloves and avoidance of drug dust exposure.

Topics: Adult; Aged; Aldehydes; Allergens; Benzodiazepines; Benzothiazoles; Case-Control Studies; Cyclohexenes; Dermatitis, Allergic Contact; Disinfectants; Ditiocarb; Female; Geriatric Nursing; Gloves, Protective; Humans; Middle Aged; Nitriles; Occupational Diseases; Patch Tests; Perfume; Retrospective Studies; Thiazoles; Thiram; Young Adult

Topics: Allergens; Balsams; Benzothiazoles; Cobalt; Dermatitis, Allergic Contact; Humans; Mercuric Chloride; Nickel; Patch Tests; Phenylenediamines; Potassium Dichromate; Reproducibility of Results

Topics: Adult; Benzothiazoles; Clothing; Dermatitis, Allergic Contact; Humans; Male; Patch Tests

Rubber gloves are one of the most frequent causes of occupational allergic contact dermatitis, especially in health care workers.. We describe 23 patients with allergic contact dermatitis due to rubber accelerators in rubber gloves, some with disseminated dermatitis, treated during a 2-year period. Three had IgE-mediated latex allergies. Sixteen were health care workers from a single institution whose dermatitis was temporally related to the switch to latex-safe gloves. Each had positive patch test reactions to 1 or more rubber accelerators, including carbamates, thiurams, 2-mercaptobenzothiazole, and 1,3-diphenylguanidine. Chemical analysis of 6 glove samples identified 2-mercaptobenzothiazole in 4 and zinc diethyldithiocarbamate in 1. There were discordances between patch test results for glove chemicals and glove swatches and between available information on chemicals used during glove production and chemicals detected during glove analysis. Although these factors may complicate the search for culprit and alternative gloves, dermatitis cleared in each of 9 patients with follow-up data and for whom alternative gloves were provided based on published information of glove composition.. Allergic contact dermatitis due to synthetic rubber gloves occurs even with the use of latex-safe products. More knowledge about chemicals present in these gloves, to which the skin is exposed during use, is necessary to prevent and treat allergic contact dermatitis.

Topics: Age Distribution; Benzothiazoles; Cohort Studies; Dermatitis, Allergic Contact; Female; Gloves, Protective; Guanidines; Health Personnel; Humans; Incidence; Latex Hypersensitivity; Male; Occupational Diseases; Patch Tests; Prognosis; Risk Assessment; Rubber; Severity of Illness Index; Sex Distribution

Mercaptobenzothiazole (MBT) is used while manufacturing natural rubber products. Our study deals with assessing its allergenic potential following dermal and oral routes of exposure, using a biphasic local lymph node assay (LLNA). Female Balb/c mice were treated with MBT (dermally 3, 10, 30% concentrations in DMSO; orally 1, 10, 100 mg/kg doses in corn oil) on the back (dermal study) or through oral administration (oral study) on days 1-3 followed by auricular application of 3, 10 and 30% concentrations, respectively, on days 15-17. End points determined on day 19 included ear thickness, ear punch weight, lymph node weight, lymph node cell count, and lymphocyte subpopulations (CD4+, CD8+, CD45+). After dermal application of 3% or 10% solution, a significant increase in cell count and lymph node weight along with significant decrease in CD8+ cells was observed. After initial oral administration of 1 mg/kg, we noticed a significant amplification in cell count. Following oral administration of 10 mg/kg, we observed a similar increase in cell count and lymph node weight. The results of our study show that the modified biphasic LLNA protocol can be used to study the sensitising potential of a compound also following the oral route of exposure.

Topics: Administration, Cutaneous; Administration, Oral; Allergens; Animals; Benzothiazoles; CD4-Positive T-Lymphocytes; CD8-Positive T-Lymphocytes; Cell Count; Dermatitis, Allergic Contact; Female; Local Lymph Node Assay; Mice; Mice, Inbred BALB C

The rubber accelerator, 2-mercaptobenzothiazole (MBT), is known to cause allergic contact dermatitis (ACD), but the mechanism is unknown. The role of the thiol group in MBT's allergenicity was investigated in the present study. Guinea pigs were sensitized to MBT using a modified guinea pig maximization test (GPMT) and reactivity was assessed toward 2-mercaptobenzothiazole disulfide (MBTS), 2-hydroxybenzothiazole (HBT; thiol-substituted), 2-(methylthio)benzothiazole (MTBT; thiol-blocked), and benzothiazole (BT; thiol-lacking). MBT and MBTS, but not BT, HBT, or MTBT, elicited ACD in MBT-sensitized animals, demonstrating that the thiol group is critical to MBT's allergenicity. In addition, both MBT and MBTS were shown to inhibit both glutathione reductase and thioredoxin reductase, and thus contribute to the stability of MBT-protein mixed disulfides. It is concluded that the probable haptenation mechanism of MBT is through initial oxidation to MBTS with subsequent reduction to form mixed disulfides with proteins.

Topics: Analysis of Variance; Animals; Benzothiazoles; Cross Reactions; Dermatitis, Allergic Contact; Disulfides; Dose-Response Relationship, Drug; Female; Glutathione Reductase; Guinea Pigs; Haptens; Immunization; Oxidation-Reduction; Rubber; Skin; Sulfhydryl Compounds; Thioredoxin-Disulfide Reductase

The rubber accelerator, 2-mercaptobenzothiazole (MBT), has been reported to cause allergic contact dermatitis from gloves and other rubber products, but its chemical fate when exposed to occupational oxidants and the mechanism of its pathogenesis are not known. It was hypothesized that the thiol group is critical to MBT's (its oxidation products or metabolites) covalent binding and/or haptenation to nucleophilic protein residues. Oxidative transformation of MBT to the disulfide 2,2'-dithiobis(benzothiazole) (MBTS) was observed within the glove matrix when hypochlorous acid, iodine, and hydrogen peroxide were used as oxidants. Cysteine reduced MBTS to MBT with subsequent formation of the mixed disulfide 2-amino-3-(benzothiazol-2-yl disulfanyl)propionic acid which was identified and characterized. Spectrophotometry and mass spectrometry experiments demonstrated the simultaneous reduction of MBTS and disulfide formation with Cys34 on bovine serum albumin, suggesting a potential route of protein haptenation through covalent bonding between protein cysteinyl residues and the MBT/MBTS thiol moiety. Metabolism of MBT using isoniazid and dexamethasone-induced rat liver microsomes, to give a protein reactive epoxide intermediate and provide an alternative protein haptenation mechanism, was not observed. The data suggest that the critical functional group on MBT is the thiol, and haptenation is via the formation of mixed disulfides between the thiol group on MBT and a protein sulfhydryl group.

Topics: Animals; Benzothiazoles; Binding Sites; Chromatography, High Pressure Liquid; Cysteine; Dermatitis, Allergic Contact; Disulfides; Gloves, Protective; Haptens; Latex; Metabolic Networks and Pathways; Oxidation-Reduction; Rats; Rats, Sprague-Dawley; Spectrophotometry; Time Factors

Topics: Benzothiazoles; Dermatitis, Allergic Contact; Dermatitis, Occupational; Humans; Male; Middle Aged; Sulfhydryl Compounds; Thiazoles

The guinea pig maximization test (GPMT) is usually performed with one moderately irritant induction dose of the allergen and gives a qualitative assessment-hazard identification-of the allergenicity of the chemical. We refined the GPMT by applying a multiple dose design and used 30 guinea pigs in a test divided into a control group and 5 test groups of 5 animals. Each group was treated with different induction concentrations of the allergens: formaldehyde, cinnamic aldehyde, propyl paraben, lidocaine, mercaptobenzothiazole or chlormethylisothiazolinone/methylisothiazolinone. The test results were analysed using a logistic multidose response model. The precision of the results depends only on the total number of animals, the dose design and the response pattern. The maximal sensitization rate for a chemical was determined, and the intracutaneous induction concentration that sensitized 50% of the animals (EC50) (or another percentage) was estimated. Further studies are needed to prove the validity of this idea. However, improvements in protocols for the GPMT are needed to reduce interlaboratory variability in results and to reduce the number of animals used for allergenicity tests.

Topics: Acrolein; Allergens; Animals; Benzothiazoles; Dermatitis, Allergic Contact; Female; Formaldehyde; Guinea Pigs; Lidocaine; Parabens; Patch Tests; Thiazoles

Topics: Acquired Immunodeficiency Syndrome; Adult; Benzocaine; Benzothiazoles; Dermatitis, Allergic Contact; Detergents; Female; Hair Dyes; HIV Seropositivity; Humans; Male; Middle Aged; Nickel; Thiazoles

5 cases of allergic contact dermatitis from rubber footwear were investigated by a combination of patch testing in patients and chemical analysis of causative rubber products. Our studies revealed 2-mercaptobenzothiazole (MBT) and benzothiazyl disulfide (MBTS) (typical allergenic accelerators) as causative chemicals in 3 cases from children's rubber shoes, ladies' rubber boots and ladies' canvas shoes. These 3 patients reacted to mercaptobenzothiazole-type accelerators including MBT and MBTS. MBT and MBTS were determined in each item of causative footwear by chemical analysis, including extraction by shaking with acetone-chloroform (1:1) mixture at room temperature and determination using reversed-phase high-performance liquid chromatography (RP-HPLC). Subsequently, we identified styrenated phenol (SP), a newly found allergenic antioxidant, as a causative chemical in a case from ladies' canvas shoes. The patient reacted to SP but not to MBT and MBTS, though SP, MBT and MBTS were determined in the causative shoes by gas chromatography (GC), GC-mass spectrometry (GC-MS) and HPLC. We also identified p-tert-butylphenol-formaldehyde resin (PTBP-F-R), (a known allergenic adhesive ingredient) as a causative chemical in a case from ladies' sneakers. The patient reacted to PTBP-F-R but not to p-tert-butylphenol (PTBP), MBT and MBTS. These 4 compounds were determined in the causative sneakers by GC, GC-MS and HPLC. Thus, our studies revealed that not only known allergens, such as MBT, MBTS and PTBP-F-R, but also a newly found one, such as SP, were important causes of allergic contact dermatitis from rubber footwear.

Topics: Adhesives; Adolescent; Antioxidants; Benzothiazoles; Dermatitis, Allergic Contact; Female; Foot Dermatoses; Formaldehyde; Humans; Male; Middle Aged; Patch Tests; Phenol; Phenols; Resins, Synthetic; Rubber; Shoes; Thiazoles

We studied 3 contact sensitizers present in rubber products, ethylbutyl thiourea (EBT), 2-mercaptobenzothiazole (MBT) and 2,2-dithio-bis-benzothiazole (MBTS), to relate the amount of sensitizer eliciting allergic contact dermatitis to the quantity leaching from a product into various biological fluids: normal saline, human plasma and 3 synthetic sweat solutions of pH 5.5 to 7.5. To determine the amount of sensitizer remaining after leaching, Soxhlet extraction with acetonitrile was subsequently performed. High-performance liquid chromatography was used for chemical analysis. 12 MBT-sensitive patients were patch tested with serial dilutions of MBT and MBTS in petrolatum. A Latin Square design was used in statistical analysis of variance of the patch test results. Large amounts of thioureas leached from 2 rubber articles eliciting thiourea dermatitis, the literature suggesting that these would have been well above the elicitation threshold. Leaching of MBTS was relatively greater than MBT into most media, whereas MBT was a more potent elicitor than MBTS at equivalent concentrations. The lowest eliciting concentration of MBT in 1 subject was 0.01%. Such information should prove helpful to manufacturers in designed products that do not release allergens sufficiently to cause reactions in consumers.

Topics: Adolescent; Adult; Aged; Benzothiazoles; Dermatitis, Allergic Contact; Diving; Dose-Response Relationship, Drug; Female; Gloves, Protective; Humans; Male; Maximum Allowable Concentration; Middle Aged; Plasma; Protective Devices; Rubber; Shoes; Skin; Sodium Chloride; Sweat; Thiazoles; Thiourea