Enterocutaneous fistulization due to Actinomyces odontolyticus. Report of a case.

A case of abdominal actinomycosis originating from the sigmoid colon is presented. Actinomyces odontolyticus was isolated; it is a rarity, but should be suspected in the case of a palpable mass and several fistulas developing after a latent period of weeks to months following surgical or inflammatory trauma. The diagnosis is made by anaerobic cultivation. Primary treatment with large doses of penicillin for several weeks may be supplemented by surgery. The strain isolated in the present case was only moderately sensitive to penicillin and was successfully treated with erythromycin.