Actinomycosis

- indolent, slowly progressive infection caused by anaerobic or microaerophilic bacteria
- most commonly caused by A.israelii
- in vivo growth of actinomycetes usually results in the formation of characteristic clumps called grains or sulfur granules
- occurs most frequently at an oral, cervical or facial site as soft tissue swelling, abscess or mass lesion that is often mistaken for a neoplasm
- abdominal and pelvic actinomycosis usually follows introduction of organism through surgery or IUCD
- thoracic actinomycosis usually follows an indolent progressive course with involvement of pulmonary parenchyma and/or pleural space
- treatment: high dose IV benzylpenicillin and surgical resection/drainage