[Tobacco contact dermatitis caused by sensitivity to sorbic acid].

Background: Contact dermatitis caused by tobacco is rare and poorly understood. In this paper, we report what is to our knowledge, the first case of tobacco contact dermatitis with identification of the causative agent.

Patients And Methods: A 46-year-old man was hospitalised for diffuse dermatitis originating in the left leg. Subsequent epicutaneous tests indicated that this dermatitis was ascribable to sensitisation to the sorbic acid present in Fucidin cream applied around a chronic wound. A persistent plaque of eczema observed on the day of examination opposite the patient's right trouser pocket suggested the implication of tobacco powder with which the pocket was soiled. An epicutaneous test using tobacco (moistened in water) proved positive (++ at 48 and 72 h). This tobacco contained sorbic acid, used as a preservative.

Discussion: The positive test for sorbic acid was relevant not only regarding the lesions on the patient's legs (application of a topical cream containing sorbic acid) but also for the lesion on the patient's thigh and for palmar dyshidrosis (through contact with strands of loose rolling tobacco). To our knowledge, this is the first recorded case of contact dermatitis caused by sorbic acid in tobacco.