Fde with fixed dose combination of ofloxacin and ornidazole with cross-sensitivity to metronidazole: A novel case

Ornidazole is a (synthetic) newer 5-nitroimidazole derivative and is commonly prescribed for amoebic dysentery in developing countries. Ornidazole has low incidence of side effects, but sometimes may cause significant allergic reactions such as fixed drug eruption (FDE). FDE is a rare adverse drug effect characterized by onset (appearance) of round or oval, erythematous macules on the skin or mucosa that can be associated with itching and burning sensation. It is a distinctive variant of drug-induced recurrent dermatosis occurring at the same site of the skin or mucous membrane. It is characterized by the appearance of a skin lesion in the instant of drug administration. The exact mechanism causing FDE is unknown. We report a case of Ornidazole induced FDE on the sole of right leg, an unusual site, in a 38 year old male patient treated for infective diarrhoea.