Sofa dermatitis: Value of patch test with 2-(thiocyanomethylthio)benzothiazole

Area of Science:

• Dermatology
• Allergology
• Toxicology

Background:

• Allergic contact dermatitis, or 'sofa dermatitis,' has been linked to various chemicals in leather furniture.
• Dimethylfumarate was an early identified allergen, but others like octylisothiazolinone, methylisothiazolinone, cobalt, and 2-(thiocyanomethylthio)benzothiazole (TCMTB) have also been implicated.

Purpose of the Study:

• To investigate the role of 2-(thiocyanomethylthio)benzothiazole (TCMTB) as a contact allergen in patients with suspected leather sofa-induced dermatitis.

Main Methods:

• Seven patients with suspected allergic contact dermatitis from leather sofas underwent patch testing.
• Testing included the European Baseline Series, additional relevant series, dimethylfumarate, and 2-(thiocyanomethylthio)benzothiazole (TCMTB).

Main Results:

• All seven patients showed a positive reaction to 2-(thiocyanomethylthio)benzothiazole (TCMTB).
• Only one patient had a positive reaction to dimethylfumarate.
• Clinical improvement was observed in all patients after removing contact with the leather sofa.

Conclusions:

• 2-(Thiocyanomethylthio)benzothiazole (TCMTB) is likely an underrecognized allergen in leather furniture and other leather products.
• Patch testing with 2-(thiocyanomethylthio)benzothiazole (TCMTB) at 0.1% in petrolatum is recommended for diagnosing contact dermatitis related to leather goods.