Thioamides, especially thiobenzanilidies and related compounds, are characterized by a wide spectrum of biological activities (antimicrobial, anthelmintic, analgesic, anti-inflammatory) depending on the type of substitution. 2.4-dihydroxythiobenzanilides have been discovered to have interesting hi vitro efficiency against dermatophytes, yeasts and moulds. The purpose of this study was to assess adverse reactions of thioamides after skin contact. The study was done on 29 guinea pigs. The guinea pig maximization test (acc. Magnusson Kligman' test) was used to estimate the risk of the skin contact allergic reactions. Skin irritation of the examined substances in different concentrations was assessed after epidermal topical application. Cross-reactions between thioamides and tetramethylthiuram disulfide was also examined. The leukocyte inhibition migration test (in vitro test) was done to confirm results of skin epidermal tests. Thioamides derivatives have very weak irritant properties and using these compounds in therapeutic concentrations (0.5-3%) has no risk of irritant adverse reaction after coming into contact with skin. Cross-reactivity was noticed among 2.4-dihydroksytiobenzamid and tetramethylthiuram disulfide. 2.4-dihydroksytiobenzamid is characterized by a weak sensitizing capacity (only 20% of animals were sensitized in GPMT) and according to OECD guidelines it may not be classified as a skin sensitizer (R43), but in special circumstances it may cause allergic contact dermatitis.
