Thiourea compounds are mainly used as accelerators in the rubber industry, but also in other industries, e.g., as
antioxidants in the graphics industry.
Thiourea compounds may provoke
allergic contact dermatitis, although the number of reported cases is relatively low. During 1985-1991, we had 5 patients with allergic patch test reactions caused by
thiourea compounds. 1 of our patients had to use a knee
brace after an occupational accident. He developed
allergic contact dermatitis caused by the knee
brace, probably because he had become sensitized to
diethylthiourea. 2 patients were probably sensitized by
diphenylthiourea in
neoprene gloves. A florist had an allergic patch test reaction to
diphenylthiourea and might have been sensitized by fungicides or pesticides, which break down into thioureas. It is often difficult, however, to detect the source of
thiourea compound sensitization. If the patient has
contact dermatitis and has been exposed to products that may contain
thiourea compounds (or compounds that break down into
thiourea compounds), such as rubber,
PVC plastic or adhesive, diazo paper, paints or glue remover, anticorrosive agents, fungicides or pesticides, patch testing with a series of
thiourea compounds needs to be performed. If patch testing with
thiourea compounds is not performed,
allergic contact dermatitis caused by
thiourea compounds is not likely to be diagnosed.