thiourea and Dermatitis--Contact

In predicting human skin sensitization due to possible risky chemicals, it is not sufficient to evaluate solely the minimum induction dose (MID) or the standard challenge dose (SCD) in the Guinea Pig Maximization Test (GPMT). Nakamura et al. (1994) (Nakamura, A., Momma, J., Sekiguchi, H., Noda, T., Yamano, T., Kaniwa, M., Kojima, S., Tsuda, M., Kurokawa, Y., 1994. A new protocol and criteria for quantitative determination of sensitization potencies of chemicals by guinea pig maximization test. Contact Dermatitis 31, 72-85) previously measured the residual dose of chemicals in the products implicated in human allergic accidents, and stated that '... the level of chemical in the products (direct exposure-dose = DED) was similar to or higher than value of sensitization potency.' However, several of the chemicals listed in their article, show an even lower value of sensitization potency than the DED, although a potential correlation between results of the GPMT and the DED was seemed to be evident; a key question about the essential rule of those parameters therefore remains open. Using the data of Nakamura et al. (1994), we analyzed the functional rules of the three independent parameters, the MID, the SCD, and the DED on which the GPMT is based. Calculations of the degree of allergic reactions elicited in humans provided a range of discrimination constants (D) using the formula; D = DED/(MID*SCD). Possible human allergic accidents may be predicted when the dose of a candidate chemical in a chemical product (equal to DED) exceeds the value; D*(MID*SCD), following the correct evaluation of the MID as well as the SCD.

Topics: Allergens; Animals; Dermatitis, Contact; Dose-Response Relationship, Drug; Drug Hypersensitivity; Guinea Pigs; Household Products; No-Observed-Adverse-Effect Level; Phenylenediamines; Skin; Thiourea; Toxicity Tests

Contact sensitivity of four thiourea rubber accelerators, diphenylthiourea (DPTU), dilaurylthiourea (DLTU), dibutylthiourea (DBTU) and diethylthiourea (DETU), was evaluated by a new sensitive mouse lymph node assay (SLNA) and the murine local lymph node assay (LLNA). The results of the SLNA and LLNA were compared with the data of the guinea pig maximization test (GPMT). In the LLNA and SLNA, the sensitizing activity was measured as a function of draining lymph node activation following application of the test chemicals. Of these four thioureas, three (DETU, DBTU and DPTU) were not classified as skin sensitizers in the LLNA. The SLNA successfully detected the sensitivity of all thioureas tested. This result indicated that the SLNA was, in these cases, more sensitive than the LLNA for identification of contact allergens. The order of sensitization potential observed from the SLNA was DPTU (greatest), DLTU, DBTU and then DETU (least). The predictions of sensitizing potential and the order of the sensitizing capacity of four thioureas by the SLNA and the GPMT are very similar.

Topics: Administration, Topical; Animals; Dermatitis, Contact; Female; Guinea Pigs; Injections, Intradermal; Lymph Nodes; Mice; Mice, Inbred BALB C; Species Specificity; Thiourea

Topics: Dermatitis, Contact; Female; Foot Dermatoses; Humans; Middle Aged; Phenylenediamines; Purpura; Shoes; Thiourea

A cleaning woman in a restaurant became sensitized to thiourea in a silver polish. The dermatitis persisted for several months and occasionally flared up after exposure to sunlight, even after she no longer used the product. Patch testing and photopatch testing showed that she had both contact and photocontact allergy.

Topics: Administration, Topical; Adult; Anti-Inflammatory Agents; Dermatitis, Contact; Dermatitis, Occupational; Female; Glucocorticoids; Humans; Patch Tests; Photosensitivity Disorders; Thiourea; Time Factors

Topics: Adult; Dermatitis, Contact; Female; Humans; Male; Patch Tests; Thiourea

Topics: Animals; Chemical Industry; Dermatitis, Contact; Dermatitis, Occupational; Guinea Pigs; Humans; Immunity; Rats; Thiocyanates; Thiourea

Topics: Adult; Dermatitis, Contact; Female; Humans; Male; Middle Aged; Spain; Thiourea

Topics: Adolescent; Blepharitis; Dermatitis, Contact; Eye Protective Devices; Humans; Male; Patch Tests; Protective Devices; Swimming; Thiourea

Topics: Adult; Copying Processes; Dermatitis, Contact; Dermatitis, Occupational; Humans; Male; Thiourea

Topics: Adult; Dermatitis, Contact; Dermatitis, Occupational; Dimaprit; Humans; Isothiuronium; Male; Patch Tests; Thiourea

Topics: Dermatitis, Contact; Dermatitis, Occupational; Detergents; Humans; Male; Middle Aged; Patch Tests; Thiourea

Topics: Dermatitis, Contact; Dermatitis, Occupational; Dimaprit; Humans; Isothiuronium; Male; Middle Aged; Thiourea

Topics: Animals; Dermatitis, Contact; Guinea Pigs; Isothiocyanates; Skin Tests; Thiocyanates; Thiourea

Topics: Abietanes; Aniline Compounds; Dermatitis, Contact; Diterpenes; Eczema; Formaldehyde; Humans; Organophosphates; Organophosphorus Compounds; Paper; Phenanthrenes; Thiourea; Trityl Compounds

Topics: Animals; Dermatitis, Contact; Dermatitis, Occupational; Dimaprit; Guinea Pigs; Humans; Isothiuronium; Patch Tests; Photography; Thiourea

28 patients reacting to a PVC adhesive tape used in routine patch testing gave positive reactions to diphenylthiourea (DPTU) and to phenylisothiocyanate (PITC) in low concentrations. DPTU is a heat stabilizer in the PVC and is partly decomposed to PITC. The two substances were found in another type of PVC. Thioureas giving isothiocyanates are also used in certain types of rubber. Isothiocyanates are present in plants, mainly of the Cruciferae family, and are also formed from thiuram sulfides and thiocarbamates. The connection between isothiocyanates derived from different sources should be investigated.

Topics: Adhesives; Dermatitis, Contact; Female; Humans; Isothiocyanates; Male; Patch Tests; Polyvinyl Chloride; Thiocyanates; Thiourea

Topics: Adult; Apolipoproteins; Apolipoproteins E; Dermatitis, Contact; Diving; Humans; Male; Skin Tests; Thiourea

Topics: Acne Vulgaris; Adolescent; Adult; Copper; Dermatitis; Dermatitis, Contact; Diving; Female; Granuloma; Hair Color; Humans; Larva Migrans; Male; Mycobacterium Infections; Seaweed; Skin Diseases; Skin Ulcer; Swimming; Thiourea

Topics: Cross Reactions; Dermatitis, Atopic; Dermatitis, Contact; Humans; Thiourea

Our patient was a 24-year-old female textile cutter who had a conjunctivitis and an erythematous itching dermatitis of the eyelids, nasal mucous membranes, and the corners of the mouth. The patch tests with the standard series and a pharmaceutical test battery were negative. Further epicutaneous testing revealed a strong positive reaction to the textile cutting patterns she handled, which were duplicated by diazo processing. Specifically, the contact dermatitis reaction was caused by dimethylthiourea, an additive in diazo-sensitized paper.

Topics: Adult; Conjunctivitis; Dermatitis, Contact; Dermatitis, Occupational; Female; Humans; Textile Industry; Thiourea

Ten patients with severe foot dermatitis were found to be highly allergic to innersole material prepared by Spenco Medical Corporation and used in Nike athletic shoes. Contact allergy testing showed sensitivity to ethyl butyl thiourea, a chemical accelerator in some neoprene (polychioroprene) rubber products. The dermatitis was recalcitrant and in many cases persisted long after discontinuance of wearing Nike shoes, raising the concern that traces of ethyl butyl thiorea or cross-reacting chemicals may be present in other footwear.

Topics: Adult; Allergens; Dermatitis, Contact; Foot Dermatoses; Humans; Male; Patch Tests; Shoes; Thiourea

As a follow-up of a preliminary trial, the therapeutic results obtained in 40 cases of acute and chronic dermatitis by the topical application of 10-undecen-1-yl-pseudothiourea hydroiodide (AHR-1911) in an evanescent vehicle containing triethanolamine stearate are presented. The treatment led to complete remission in 14/40 and to favorable results in 18/40 cases. In 2 out of 3 cases of infantile atopic dermatitis improvement was followed by relapse. The responsiveness to AHR-1911 of patients with delayed hypersensitivity, which requires steroids for treatment, is considered of clinical importance. The prompt action of the drug in acute dermatitis, such as is produced by insect-bites, appeared to be impressive. None of the total of 50 cases treated by the author with this new preparation showed any manifestation of intolerance or reaction to the drug.

Topics: Acute Disease; Administration, Topical; Adult; Anti-Inflammatory Agents; Child; Chronic Disease; Dermatitis; Dermatitis, Contact; Drug Evaluation; Ethanolamines; Humans; Infant; Insect Bites and Stings; Isothiuronium; Pharmaceutical Vehicles; Stearates; Thiourea