Allergic Contact Dermatitis due to Dazomet Absorbed by Agricultural Rubber Boots

Abstract

Dazomet, a soil fumigant, decomposes when it comes into contact with the ground or irrigation water, forming methyl isothiocyanate (MITC), which is effective against many bacteria and fungi. We report here a case of allergic contact dermatitis to dazomet.CASE REPORTA 67-year-old male farmer presented with an acute onset of itchy bullae and erythema on his feet. He had a history of diabetes mellitus. On physical examination, multiple bullae and erythema on the left sole, foot, and lower leg were observed, as well as erythema on the right foot (Fig. 1a). Additional bullae developed on the right sole 2 days later. To resolve the severe pruritus and extensive bullae formation prednisolone 20 mg/day was administered for 3 days, followed by 10 mg/day for 10 days. Diflorasone diacetate was used as topical steroid. During the 3 months after steroid cessation, bullae with pruritus occasionally developed on the patient’s feet. Frequent interviews and several laboratory examinations, including skin biopsy, skin cultures, and blood tests, did not reveal the cause. Eventually, the patient’s occupation and the lesion sites led us to suspect his rubber boots (Fig. 1b). Patch tests were performed on the patient’s boots. Thin square pieces (5×5 mm) of the outer surface, inner surface, inner insole, and bottom insole of the boots were applied, avoiding pressure effects, on the patient’s back with “Patch Tester Torii” (Torii Pharma -ceutical, Tokyo, Japan), an adhesive bandage, for 48 h. Results were obtained after 2 and 3 days of patch test application on the basis of the scoring system by the International Contact Dermatitis Research Group. Positive results were obtained for the outer surface (D2