Stephanie Liu, MD; Charissa M. Etrheim, MD; Kevin M. McDonald, MD
WMJ. 2024;123(4):311-314.
ABSTRACT
Introduction: Actinomycosis is a rare, chronic, progressive bacterial infection caused by Actinomyces species with a reported incidence of 1 in 300 000. Actinomycosis has variable presentations and is commonly mistaken for malignancy and other infections, leading to delays in diagnosis and appropriate treatment. Actinomyces is a commensal bacteria found in the mouth, gut, and genitourinary tract. Actinomycosis tends to take advantage of anatomical defects for contiguous spread and can cause fistulas, sinus tracts, abscesses, and intrauterine device-associated infections.
Case Presentation: A 78-year-old White male with known dental caries came to a primary care clinic 2 days after noticing a painless, nonbleeding mass eroding from his hard palate. After a tissue biopsy of the mass showed a diagnosis of actinomycosis and advanced imaging showed no intracranial involvement, he was treated with a 6-month course of antibiotics, including oral amoxicillin, oral amoxicillin-clavulanate, and intravenous ertapenem.
Discussion: There are several case reports of actinomycosis with variable presentations, such as cutaneous nodules and sinus tracts. These cases frequently are associated with dental infections and procedures, trauma, oral surgery, or prior head and neck radiation. The condition is often mistaken for other infections or malignancy, which can delay appropriate treatment and increase the risk of complications.
Conclusions: Actinomycosis is a rare bacterial infection with variable presentations occurring throughout the body. This patient responded well to a prolonged course of intravenous and oral antibiotics and had complete healing of his hard palate defect. Actinomycosis is frequently misdiagnosed, leading to delays in appropriate treatment.