title: Sensitizing potential of chlorothalonil in the guinea pig and the mouse.
abstract: The fungicide chlorothalonil is used extensively under several tradenames for the protection of various horticultural and fruit crops and bananas against fungal infections. It is also used as fungicide in wood preservation and as a preservative in paints. Clinical experience has shown chlorothalonil to be a contact allergen and several cases of allergic contact dermatitis attributed to chlorothalonil have been described. 2 previous guinea pig maximization test studies have shown the sensitizing potential of chlorothalonil to be high. The sensitizing property of chlorothalonil was studied by us with the predictive test methods the local lymph node assay and the cumulative contact enhancement test. In the local lymph node assay, chlorothalonil induced a dose-dependent increase in proliferation with a maximal stimulation index of 19.2 and 27.2. In the cumulative contact enhancement test, a statistically significant dose-dependent high sensitization rate was seen with a maximal sensitization rate of 100%. In conclusion, it is evident that chlorothalonil is an extremely potent contact allergen, inducing sensitization using only topical exposure on intact skin.
authors.affiliation: Department of Medicine, Occupational and Environmental Dermatology, Karolinska Institutet, Stockholm, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Boman
authors.forename: J
authors.initials: J
authors.lastname: Montelius
authors.forename: R L
authors.initials: RL
authors.lastname: Rissanen
authors.forename: C
authors.initials: C
authors.lastname: Lidén
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D005659:Fungicides, Industrial / Q000494:pharmacology*; D006168:Guinea Pigs; D007114:Immunization / Q000379:methods*; D008198:Lymph Nodes / Q000187:drug effects; D051379:Mice; D023421:Models, Animal; D009570:Nitriles / Q000494:pharmacology*; D011237:Predictive Value of Tests; D012016:Reference Values; D012680:Sensitivity and Specificity; D012882:Skin Tests; D013045:Species Specificity
chemical_list: D005659:Fungicides, Industrial; D009570:Nitriles; C005806:tetrachloroisophthalonitrile