Diagnosis: Cervicofacial actinomycosis
Our patient’s dental sinus was a form of cervicofacial actinomycosis, the most common Actinomyces infection in humans. Cervicofacial actinomycosis (or “lumpy jaw”) is typically a slowly progressive subacute disease that can begin spontaneously or one to several weeks after dental extraction or local trauma. The lesion soon adheres to the underlying structures and may develop sinus tracts that exude characteristic sulfur granules. These bacteria collections are suggestive — but not diagnostic — of Actinomyces infection. Draining sinuses may involve the intraoral surfaces, tongue, facial sinuses, and meninges and rarely cause osteomyelitis or periostitis of the mandible.
Cervicofacial actinomycosis is commonly seen in patients with poor oral hygiene or periodontal abscesses. The condition may also present with diffuse swollen soft tissues and nodules of the jaw. In addition to the head and neck, Actinomyces infections may also involve the thorax, pelvis, or, rarely, the central nervous system or bones. The most often found Actinomyces isolates are A. israelii and A. gerencseriae.
Diagnosis is made on the basis of Gram’s stain and culture of the sulfur granules or biopsy specimens. Culture is the least reliable method. On histologic sections, repeat sectioning through the paraffin block may be required. Serodiagnosis by precipitating antibodies has not been effective.
The differential diagnoses are fairly limited. They include squamous cell carcinoma, basal cell carcinoma, other cutaneous malignancies, foreign-body granulomas, cutaneous tuberculosis, and other bacterial infections.
Recommended treatment is IV penicillin G for at least four weeks, followed by oral penicillin for 6-12 months. In vivo development of penicillin resistance has not been reported, although some evidence exists to support in vitro resistance. A persistent abscess that does not respond to initial treatment may indicate co-infection with other bacteria, such as Actinomyces actinomycetemcomitans, ß-lactamase producing Bacteroides, Staphylococcus aureus, or Enterobacteriaceae. In those instances, the suggested treatment includes surgical drainage and excision of sinus tracts, necrotic tissue, and recalcitrant fibrotic lesions.
Our patient’s punch biopsy revealed acute and chronic inflammation, but no organisms were found on biopsy or culture. She was started on IV penicillin. Excision of the sinus tract is planned following the completion of adequate antibiotic treatment.