Makindo Medical Notes

Actinomyces israelii infection is notable for the formation of multiple abscesses and sinus tracts that may discharge sulfur granules.

About

• James Adolf Israel, a German surgeon, first described this infection.
• Causes abscess formation and chronic infections, often involving multiple organs.
• Actinomyces israelii is a commensal organism, commonly found in the oropharynx and gastrointestinal tract.

Characteristics

• Gram-positive, non-acid-fast anaerobic bacillus.
• Can take both rod and branching filamentous forms.
• Infections produce characteristic visible granules known as "sulfur granules."

Aetiology

• Normally commensal, but can become pathogenic in the presence of trauma or devitalized tissue.
• Actinomyces israelii is the major pathogen responsible for actinomycosis.
• Infection is commonly associated with poor oral hygiene, tooth extractions, or intrauterine devices (IUDs).

Clinical Features

• Cervicofacial actinomycosis ("lumpy jaw"):
  • Follows dental trauma, tooth extraction, or poor oral hygiene.
  • Presents with firm, painless swelling and multiple draining sinus tracts that discharge sulfur granules.
• Thoracic actinomycosis:
  • Caused by aspiration, leading to abscess formation in the lungs and mediastinum.
• Brain abscesses:
  • Focal neurological signs and symptoms due to abscess formation.
• Abdominal/Pelvic actinomycosis:
  • Can occur following IUD insertion, leading to pelvic pain, masses, and inflammation.
  • Chronic granulomatous appendicitis may mimic malignancy, with fistulas and inflammatory masses.
  • Symptoms include abdominal pain, weight loss, fever, and occasionally a palpable mass.

Investigations

• Full blood count (FBC): May show elevated white cell count (WCC), anaemia, and raised ESR and CRP.
• Chest X-ray (CXR) may reveal lesions in thoracic actinomycosis.
• Ultrasound or CT scan: Useful for identifying large inflammatory masses in the abdomen or pelvis.
• Culture and sensitivities: Essential for confirming diagnosis and guiding treatment.

Management

• Prolonged course of Penicillin G is the treatment of choice, often lasting weeks to months.
• Doxycycline may be used for those allergic to penicillin or who are not pregnant (refer to BNF for guidance).
• Surgical management is often necessary, particularly when cancer is suspected in the differential diagnosis or in cases of extensive abscess formation.