Breath malodor in an asthmatic patient caused by side-effects of medication: a case report and review of the literature.

The purpose of this report is to document the presence of dimethyl sulfide in mouth air as the predominant volatile sulfur compound (VSC) in an asthmatic patient who was regularly taking suplatast tosilate. The patient was a 33-year-old woman who complained of bad breath. She had been diagnosed as having asthma and was receiving periodical medical examinations once a month. VSC in her mouth air were measured with a gas chromatograph. Oral physiotherapy was also carried out to remove any oral malodor of which the source was intraoral. With the improvement in oral hygiene and periodontal conditions, the level of VSC was reduced but dimethyl sulfide still remained as the predominant VSC. Dimethyl sulfide metabolized from suplatast tosilate may be a potential cause of halitosis.