Abstract: We are reporting an unusual case of actinomycosis infection which presented with subtalar arthritis. Actinomycosis is a chronic granulomatous disease caused by Gram-positive anaerobic bacteria. Actinomycosis is very rare and of the cases reported Cervicofacial infection is the most frequent clinical presentation. Hematogenous osteomyelitis at distant sites can occur in the rare instance in immunocompromised or pediatric patients, only a few cases have been reported in healthy patients.
Case Report: A 39years, female patient presented with pain, swelling around the right ankle for 4 years with healed sinuses over the lateral aspect. She was treated for the discharging sinuses of right ankle and foot 5 years back with antibiotics and surgery elsewhere. She had a history of taking treatment (ATT for 6months) for pulmonary TB, 10years back. X-rays and Magnetic resonance imaging showed a distorted subtalar joint with multifocal intraosseous lesions in the calcaneum. Curettage and subtalar arthrodesis with Cannulated cancellous screws was done and supported with short-term immobilization. The tissue culture, fungus culture, acid-fast bacillus (AFB) culture, AFB smear, and tuberculosis polymerase chain reaction test results of intraop samples were negative. A pathologic examination confirmed the presence of actinomycosis. The patient was treated with intravenous penicillin for 2 weeks followed by Oral Doxycycline for 6 weeks, given no evidence of active infection intraoperatively. After 1year follow-up, the patient had no signs of recurring infection or complications and she is ambulant pain-free.
Conclusion: Actinomycosis of the foot, though rare, can mimic tuberculosis in areas with a high prevalence of tuberculosis. In patients with recurrent discharging sinuses, a high index of suspicion is warranted to early diagnose it.
