Actinomycosis: etiology, clinical features, diagnosis, treatment, and management

Abstract

Actinomycosis is a rare chronic disease caused by Actinomyces spp., anaerobic Gram-positive bacteria that normally colonize the human mouth and digestive and genital tracts. Physicians must be aware of typical clinical presentations (such as cervicofacial actinomycosis following dental focus of infection, pelvic actinomycosis in women with an intrauterine device, and pulmonary actinomycosis in smokers with poor dental hygiene), but also that actinomycosis may mimic the malignancy process in various anatomical sites. Bacterial cultures and pathology are the cornerstone of diagnosis, but particular conditions are required in order to get the correct diagnosis. Prolonged bacterial cultures in anaerobic conditions are necessary to identify the bacterium and typical microscopic findings include necrosis with yellowish sulfur granules and filamentous Gram-positive fungal-like pathogens. Patients with actinomycosis require prolonged (6- to 12-month) high doses (to facilitate the drug penetration in abscess and in infected tissues) of penicillin G or amoxicillin, but the duration of antimicrobial therapy could probably be shortened to 3 months in patients in whom optimal surgical resection of infected tissues has been performed. Preventive measures, such as reduction of alcohol abuse and improvement of dental hygiene, may limit occurrence of pulmonary, cervicofacial, and central nervous system actinomycosis. In women, intrauterine devices must be changed every 5 years in order to limit the occurrence of pelvic actinomycosis.

Keywords:

• Actinomyces spp.
• sulfur granule
• osteomyelitis
• lumpy jaw syndrome

Acknowledgments

The authors acknowledge Dr Frédérique Lebreton, pathologist, and our colleagues at the Lyon Bone and Joint Infection Study Group, as follows. Physicians: Tristan Ferry, Thomas Perpoint, André Boibieux, François Biron, Florence Ader, Judith Karsenty, Florent Valour, Fatiha Daoud, Johanna Lippman, Evelyne Braun, Marie-Paule Vallat, Patrick Miailhes, Christian Chidiac, and Dominique Peyramond. Surgeons: Sébastien Lustig, Philippe Neyret, Elvire Servien, Olivier Reynaud, Vincent Villa, Olivier Guyen, Jean- Baptiste Bérard, Olivier Cantin, Frédéric Dalat, Romain Desmarchelier, Michel-Henry Fessy, Cédric Barrey, Francesco Signorelli, Pierre Breton, Ali Mojallal, Fabien Boucher, and Hristo Shipkov. Microbiologists: Frederic Laurent, François Vandenesch, Jean-Philippe Rasigade, and Céline Dupieux. Nuclear medicine specialists: Isabelle Morelec, Marc Janier, and Francesco Giammarile; PK/PD specialists: Michel Tod, Marie-Claude Gagnieu, and Sylvain Goutelle. Clinical research assistant: Eugénie Mabrut.

Disclosure

The authors report no conflicts of interest in this work.