diphenylthiourea and Dermatitis--Occupational

About 21% of the patients with occupational contact dermatitis registered in the Information Network of Departments of Dermatology (IVDK) in the years 1995-2001 were patch tested due to suspected rubber glove allergy. We analysed reaction frequencies to thiurams, dithiocarbamates, mercaptobenzothiazole (MBT) and its derivatives, thioureas, and 1,3-diphenylguanidine (1,3-DPG). Thiurams were by far the most frequent rubber allergens in these patients (16.2% positive reactions, age- and sex-standardized), and the reaction frequency showed a decline from 20.9% in 1997 to 12.8% in 2000. However, this trend was not statistically significant, and was followed by an increase to 16.5% in 2001. All other rubber allergens showed no time trend at all. Although, according to manufacturers' information, the use of dithiocarbamates and MBT derivatives in rubber glove production increased in recent years, these allergens elicited positive reactions in only about 3% of the patients tested, and showed no increasing trend. Thioureas and 1,3-DPG are not widely used in rubber glove production, and play only a minor role in rubber glove contact allergy. Most of the positive reactions to 1,3-DPG are probably false-positive, irritant reactions.

Topics: Adult; Allergens; Benzothiazoles; Dermatitis, Allergic Contact; Dermatitis, Occupational; Female; Germany; Gloves, Protective; Hand Dermatoses; Humans; Latex Hypersensitivity; Male; Thiazoles; Thiocarbamates; Thiourea; Thiram

Topics: Allergens; Butylated Hydroxytoluene; Dermatitis, Allergic Contact; Dermatitis, Occupational; Diagnosis, Differential; Humans; Male; Microcomputers; Middle Aged; Patch Tests; Thiourea; Thumb

11 cases of contact dermatitis from Vulkan heat retainers are reported. The skin eruptions started on days 1-11 after the 1st day of exposure. The clinical picture varied from eczema through urticaria to purpura. In some cases, the symptoms were severe. Patch testing was performed in 10 individuals and all reacted positively to the heat retainer and/or the rubber glue used in the heat retainer. A series of rubber chemicals was patch tested in 7 patients and all showed positive reactions to diphenylthiourea (DPTU), and all but one to ethylene thiourea (ETU). TLC examination revealed a spot with the same RF-value as DPTU in extracts of the adhesive, but no spot corresponding to ETU. There were no indications of impurities in the test preparations of DPTU and ETU. By HPLC, the content of DPTU in the adhesive was determined as 0.6% w/w.

Topics: Adhesives; Adult; Aged; Dermatitis, Occupational; Female; Hot Temperature; Humans; Hypersensitivity, Delayed; Male; Middle Aged; Patch Tests; Rubber; Thiourea

Topics: Adult; Biphenyl Compounds; Dermatitis, Occupational; Humans; Male; Neoprene; Protective Clothing; Thiourea