Contact dermatitis caused by a new rubber compound detected in canvas shoes

Abstract

SummaryBackground. In 2015 and 2016, female patients in Flanders consulted a dermatologist because they developed skin lesions after wearing a specific brand of canvas shoes. Objectives. To identify the culprit allergen in the shoes. Methods. Eighteen young females aged 14-22 years presented with itching and erythematous to purple-coloured eczematous lesions on both feet. They were patch tested by 10 dermatologists with the European baseline series. Some patients underwent testing with additional series. Pieces of the shoe fabrics were tested in 11 of 18 patients. Chemical analysis of the shoe materials was performed. Finally, patients were tested with a thin-layer chromatogram of the shoe extracts and dilutions of the suspected rubber compound. Results. All 18 patients showed positive reactions to thiuram mix. Ten of 11 patients reacted to a piece of shoe fabric. Chemical analysis showed the presence of dimethylthiocarbamylbenzothiazole sulfide (DMTBS). No thiurams were detected. Four patients tested with the chromatogram developed positive reactions to DMTBS. Positive reactions to low concentrations were observed in the 4 patients tested with a DMTBS dilution series; one patient reacted to 0.00001% in acetone. Conclusions. DMTBS, the culprit allergen, is a component formed during rubber vulcanization that probably cross-reacts with the thiuram mix.Key words: allergic contact dermatitis; CAS no. 3432-25-5; chemical analysis; degradation; dimethylthiocarbamylbenzothiazole sulfide; rubber chemicals; shoes; thin-layer chromatogram; thiuram derivatives; vulcanization.Allergic contact dermatitis of the feet accounts for approximately 0.5-11% of all patients referred for patch testing. Risk factors for shoe dermatitis include heat, friction,

Allergic contact dermatitis caused by dimethylthiocarbamylbenzothiazole sulfide (DMTBS) in canvas shoes: in search of the culprit allergen

“…During the vulcanization process, thiuram derivatives react with mercaptobenzothiazoles, forming new compounds with both dithiocarbamate and mercaptobenzothiazole structures, such as DMTBS (Fig. ).…”

“…However, several months later, a number of Belgian patients presented with shoe dermatitis caused by similar Sperry Top Sider® canvas sneakers. HPLC analysis of a shoe of one of these patients showed high amounts of DMTBS in the water‐repellent inner layer of the shoe . Consequently, a new extract was made of the water‐repellent inner layer of the shoe of the Dutch patient, with the same method as before.…”

Contact Allergy in Children

“…Dermatitis generally affects the back of the feet, most often due to chromium salts and glue components and most often due to rubber additives on the soles. Dimethylthiocarbamyl benzothiazole sulfide (DMTBS): a new component formed during rubber vulcanization, chemically related to thiuram derivatives, was recently described as the culprit in linen shoes causing dermatitis of the back of the feet in several young girls [130].…”

Contact Allergy—Emerging Allergens and Public Health Impact

“…Chromium-tanned leather is a well-known source of ACD to chromium, see above under "Metals". A case of foot dermatitis related to the use of Sperry Top Sider™ canvas sneakers in an 18-year-old Dutch female as well as a large case series involving 18 young females (age 14-22 years) in Belgium suffering the same type of dermatitis after wearing these brand shoes were reported in which there was no leather contact [251,252]. Strikingly, all patients reacted to the screening allergen thiuram mix 1% pet.…”

“…Several patients reacted, in a dilution series of DMTBS, to a ≥ 0.001% concentration in acetone, pointing to a strong sensitising potency of this compound. DMTBS seemed to have been formed from two rubber ingredients as the result of the vulcanisation process [252]. Of note, no ingredient information had been available from the manufacturer's side.…”