Etiology


Pathogen

  • Actinomyces are primarily anaerobic, gram-positive, non-acid fast, branching, rod-shaped bacteria.
  • Actinomyces bacteria, particularly Actinomyces israelii, are found in the normal oral flora.

Predisposing factors

  • Cervicofacial actinomycosis (most frequent form of actinomycosis)
    • Poor dental hygiene (e.g., dental caries)
    • Oral surgery (e.g., tooth extraction)
    • Maxillofacial trauma
    • Local tissue inflammation (e.g., tonsillitis, tumor)
    • Comorbidities (e.g., diabetes)
  • Abdominal and pelvic actinomycosis (See PID)
    • Intestinal surgery
    • Foreign body ingestion
    • Tumor
    • Ascending infection from the uterus, associated with intra-uterine contraceptive devices
  • Thoracic actinomycosis
    • History of aspiration
    • Recent oral infection

Clinical features


  • Cervicofacial actinomycosis
    • Slowly progressive mass in the neck and/or face; most commonly in the mandible region
    • Usually painless nodular lesions
    • Becomes indurated with purulent discharge that contains sulfur granules from fistulae and draining sinus tracts.Pasted image 20240320110002.png
      • Sulfur granules refer to macroscopic grains – approx. 1 mm in diameter – of hard clumps of bacterial filaments, pus, debris, and hyaline. The granules appear yellow within pus, although despite the name they do not contain sulfur.
  • Thoracic actinomycosis
    • Cough, chest pain
    • Possible hemoptysis with yellow granules

Tip

Definitive diagnosis is based on the identification of actinomycotic sulfur granules or bacteria.

Diagnostics


  • Microscopy: direct visualization and staining of specimen → accumulations of radially protruding and branching Actinomyces (conglomerates with a “cauliflower-like” appearance) that are surrounded by numerous granulocytesL61462.jpg

Pasted image 20230807151432.png

An aggregate of basophilic bacteria with radially branching filaments is visible at the center, which has a cauliflower-like appearance (yellow overlay).
The bacteria are surrounded by numerous granulocytes, resulting in a lesion with a rosette-like pattern (green overlay).

This is the typical histopathological appearance of a yellow “sulfur granule” caused by actinomycosis.

Treatment


Penicillin