Facial dermatitis caused by chlorothalonil in a paint

A case of acute facial dermatitis caused by staying in a summer cottage is described. Patch testing revealed contact allergy to the paint På Trä Lasur, and to chlorothalonil. Chlorothalonil was used as a pesticide in the paint. Chemical analyses using high-performance liquid chromatography and gas chromatography/mass spectrometry were performed to reveal the purity of the chlorothalonil. Chlorothalonil has earlier been described as a contact allergen, sometimes causing facial dermatitis. The reason for localization to the face has not before been discussed. It is now suggested that it might be due to the high vapour pressure of chlorothalonil. It is concluded that products containing chlorothalonil are unsuitable for indoor use.