Updated: 6/6/2018

Actinomyces israelii

Review Topic
  • A 45-year-old man comes into urgent care for several months of lumps on his neck. Since he has not had any fevers or pain, he had ignored the lumps and had not sought treatment. He states that he has had multiple dental procedures but no other surgeries. On physical exam, he has multiple dental caries and 2 large, nontender masses under his chin. Yellow pus drains from these masses. He is counseled on oral hygiene and given antibiotics.
  • Classification
    • Actinomyces israelii
      • an anaerobic, branching, filamentous gram + rod
      • produces yellow, sulfur-colored granules
    • transmission
      • direct contact with bacteria
  • Epidemiology
    • demographics
      • male > female
    • location
      • most commonly affects the face and neck
      • may also cause pelvic inflammatory disease
    • risk factors
      • poor oral hygiene
        • dental caries
        • dental extraction or procedure
      • dental trauma
      • intrauterine device (IUD)
  • Pathogenesis
    • anaerobic environment in abscess cavities allow the bacteria to flourish
  • Associated conditions
    • cervicofacial actinomycosis
  • Prognosis
    • slowly progresses over weeks to months
    • may relapse even after treatment
  • Symptoms
    • mass on the face or neck
  • Physical exam
    • may have a fever
    • facial actinomycosis
      • nontender and indurated mass
      • sinut tracts may drain thick yellow pus
      • pus may contain sulfur granules
    • cervicoactinomycosis
      • may have draining yellow pus from cervical orifice
  • Labs
    • tissue biopsy, culture, or pap smear
      • gram + branching rods
      • not acid-fast
    • microscopy of draining pus
      • yellow granules filled with bacteria
  • Making the diagnosis
    • most cases are clinically diagnosed
  • Nocardiosis
    • distinguishing factors
      • weakly acid fast and aerobic branching filamentous gram + rod
      • primarily causes pulmonary infections that can spread to central nervous system
      • SNAP = Sulfa for Nocardia; Actinomyces use Penicillin
  • Conservative
    • improved oral hygiene
      • indication
        • all patients
  • Medical
    • penicillin
      • all patients
    • tetracyclines
      • indications
        • penicillin allergy
  • Operative
    • surgical drainage or excision
      • indication
        • all patients along with antibiotics
  • Fistula formation
  • Scarring

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