Perianal actinomycosis: diagnostic and management considerations: a review of six cases.

INTRODUCTION: Primary anal actinomycosis of cryptoglandular origin, mainly due to Actinomyces israelii, a specific and rare cause of anal suppurative disease, needs to be recognized because it can be cured using specific treatments.
METHOD: Data were reviewed from 6 patients with actinomycotic anal abscesses of obvious cryptoglandular origin observed in a single proctology unit between 1983 and 2000. Therapeutic management included conventional surgical treatment of anal sepsis followed by a specific oral antibiotic therapy maintained until the surgical wound had completely healed.
RESULTS: All but one of the patients were men (median age, 53 years). All abscesses, except one, were indolent. No patient presented macroscopic "sulphur granules" in the pus, but one presented "watery pus". The diagnosis was established by histological study of the surgically excised tissue or by anaerobic culture of the pus. In the one HIV-positive patient, an uncommon organism was isolated: Actinomyces meyeri. Two cases of recurrence were observed without evidence of Actinomyces infection.
CONCLUSION: Actinomycosis should be suspected particularly in indolent anal suppuration. The absence of macroscopic "sulphur granules" does not mean this diagnosis can be ruled out. Careful histological examination of the excised tissue and appropriate anaerobic cultures of pus should be carried out to achieve complete eradication of this rare, but easily curable disease.