ABSTRACT
Metronidazole is a synthetic nitroimidazole derivative with antiprotozoal and antibacterial activities; it is extremely effective against anaerobic bacterial infections. Metronidazole is indicated for the treatment of anaerobic infections and mixed infections, surgical prophylaxis requiring anaerobic coverage, Clostridium difficile -associated diarrhea and colitis, Helicobacter pylori infection and duodenal ulcer disease, bacterial vaginosis, Giardia lamblia gastro-enteritis, amebiasis caused by Entamoeba histolytica, and Trichomonas infections. In Leuven, Belgium, in the period 1990-2014, 209 patients suspected of iatrogenic contact dermatitis were patch tested with a pharmaceutical series and with their own products; 4 (1.9%) had a positive reaction to metronidazole 1% pet. 96% of the positive patch test reactions to all topical drugs and antiseptics were considered to be relevant. The question has been raised (but not answered) whether contact allergy to metronidazole and other (nitro)imida- zoles may be overrepresented, from cross-reactivity or otherwise, in patients allergic to methylchloroisothiazolinone /methylisothiazolinone.
