Clinical Manifestations of  Actinomycosis

Actinomycosis results from pathogen introduction following

a breakdown in mucocutaneous protective barriers. Spread within the host is by

direct invasion of adjacent tissues, typically forming sinus tracts that cross tissue planes.

The most common species causing human disease is Actinomyces israelii.

There are 3 common anatomic sites of infection. Cervicofacial is most common,

often occurring after tooth extraction, oral surgery, or other oral/facial trauma

or even from carious teeth. Localized pain and induration may progress to cervical

abscess and “woody hard” nodular lesions (“lumpy jaw”), which can develop draining

sinus tracts, usually at the angle of the jaw or in the submandibular region. Infection

may contribute to recurrent or persistent tonsillitis. Thoracic disease most commonly

is secondary to aspiration of oropharyngeal secretions but can be an extension of cervicofacial

infection. It occurs rarely after esophageal disruption secondary to surgery

or nonpenetrating trauma. Thoracic presentation includes pneumonia, which can be

complicated by abscesses, empyema, and rarely, pleurodermal sinuses. Focal or multifocal

mediastinal and pulmonary masses may be mistaken for tumors. Abdominal

actinomycosis usually is attributable to penetrating trauma or intestinal perforation.

The appendix and cecum are the most common sites; signs and symptoms can mimic

appendicitis. Slowly developing masses may simulate abdominal or retroperitoneal

neoplasms. Intra-abdominal abscesses and peritoneal-dermal draining sinuses occur

eventually. Chronic localized disease often forms draining sinus tracts with purulent

discharge. Other sites of infection include the liver, pelvis (in some cases, linked to

use of intrauterine devices), heart, testicles, and brain (usually associated with a primary

pulmonary focus). Noninvasive primary cutaneous actinomycosis has occurred.

Actinomyces infections have been associated with adverse pregnancy outcomes and cases

of neonatal bacteremia have been described.