ABSTRACT
Chlorquinaldol is an organochlorine compound and a monohydroxyquinoline. An antifungal and antibacterial, chlorquinaldol was formerly used for topical treatment of skin, gastrointestinal, and vaginal infections with fungi, protozoa, and certain bacteria. Routine testing in the USA yielded low prevalences of 0.3% and 0.4% of sensitization and somewhat higher in Germany in the period 1972-1983. In Leuven, Belgium, in the period 1990-2014, iatrogenic contact dermatitis was diagnosed in 2600 individuals (17% of the total patch test population) 96% of all positive patch test reactions to topical drugs and antiseptics were considered to be relevant. Cross-reactions between halogenated hydroxyquinolines such as clioquinol (5-chloro-7-iodoquinolin-8-ol), chlorquinaldol (5,7-dichloro-2-methylquinolin-8-ol), cloxyquin (5-chloroquinolin-8-ol), oxyquinoline (8- hydroxyquinoline, non-halogenated), iodoquinol (5,7-diiodoquinolin-8-ol), halquinol (a mixture of 4 hydroxyquinolines), 5,7-dichloro-8-quinolinol and 5-chloro-8-quinolinol may occur.
