ABSTRACT
Cloxyquin is a monohalogenated 8-hydroxyquinoline with activity against bacteria, fungi, and protozoa. A 68-year-old woman was prescribed a cream containing cloxyquin 5.0%, fluprednidene acetate 1.0% and gentamicin sulfate 1.67% for a fungal infection. As the patient developed dermatitis after 2 days already, she must previously have become sensitized to cloxyquin or have cross-reacted to clioquinol, although the patient's history suggested that she had never used antimycotics and had never developed contact dermatitis. Patch tests were positive to halquinol, its ingredients cloxyquin and 5,7-dichloro-8-quinolinol, and several other hydroxyquinolines. 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-hydroxy-quinoline, 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 (2-5 [examples of references]).
