ABSTRACT
Benzethonium chloride is quaternary ammonium compounds, which may cross-react with benzalkonium chloride. It has been used in the treatment of burns, ulcers, wounds, and infected dermatoses and also present in many cosmetics, deodorants, mouthwashes, dentifrices, lozenges, and ophthalmic preparations. Cetostearyl alcohol is used as emulsifiers and can be considered as preservatives. A 19-year-old female presented with well-demarcated adult-fist sized dark-reddish patch on the left shin. She had applied Senepul(R) (disinfectant solution) 3 months ago due to scratching wound and applied Travogen(R). Patch test with Korean standard series and the ingredients of used topical agents showed positive reactions to benzethonium chloride and cetostearyl alcohol.