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Clinical Meetings at RH Year 2010

2010 - An indolent infection

Dr Raymond Tso, Dr KS Lau and Dr CW Lam, Department of Medicine, Ruttonjee and Tang Shiu Kin Hospital



Case History
A 50 year-old housewife, with history of schizophrenia on Prozac and Clozapine, was referred from Chest Clinic to Ruttonjee hospital because of on and off cough with blood stained sputum for four weeks.

She was a non-smoker; non-drinker and enjoyed her good functional status. Her symptoms were only associated mild weight loss and reduced appetite. In reviewing her symptoms, she denied any dyspnoea, epistaxis, fever or nasal congestion. There was no relevant travel or contact history. On examination she was afebrile and all vital signs were stable. Inspiratory crepitations were noted over her right upper lung field. Initial chest roentgenogram revealed peripherally located right upper lobe infiltrate. (Fig. 1)


Her baseline blood tests revealed mild elevation of white cell count with neutrophilia. A course of Augmentin was given empirically and her symptoms subsided for several months. There was no radiological improvement in her follow up visits (Fig. 2), and her dry cough persisted.


A contrast computed tomography (CT) of the chest revealed consolidations over apical and posterior segments of right upper lobe and a tiny calcified granuloma in the right middle lobe, with no mediastinal or hilar lymphadenopathy. (Fig. 3)

Due to the persistent right upper lobe consolidation, bronchoscopy was performed. The tracheobronchial tree was normal and the transbronchial biopsy (from right upper lobe), bronchial aspirates for culture, acid-fast stain and cytology were all negative. Since the subsequent follow-up CXRs showed worsening of her right upper lobe infiltrate, another CT was repeated and revealed worsening right upper lobe consolidation that involved all three segments of right upper lobe. (Fig. 4)


With the radiological and clinical deterioration, a CT- guided fine needle aspiration biopsy was performed which showed inconclusive inflammatory changes. Further workup revealed elevation of erythrocyte sedimentation rate (ESR) and C-reactive protein, negative ANCA and normal nasopharyngeal exam. Open lung biopsy by VATS was subsequently performed, which revealed xanthogranulomatous inflammation with Splendore-Hoeppli phenomenon. (Fig. 5)


Multiple colonies of Gram and Grocott stain positive filamentous organisms were identified to be Actinomyces. (Fig. 6) Intraoperative swab from an abscess grew bacteriodes and sputum grew Enterobacter. Intravenous Tienam was started and was later switched to Pen G after two weeks. Pen G was given for another two weeks and she was eventually discharged with 8 months of Augmentin. Multiple dental caries were later identified and with extractions done by dental surgeon. Marked resolution of her right upper lobe infiltrate was found after 9 months of treatment.


Discussion
Actinomycosis is an indolent infection caused by normal oral flora Actinomyces spp. It belongs to a family of Gram-positive and anaerobic bacteria that exist on the soil. A. israelli is the most common subtype that causes human disease and it produces sulphur granules. Actinomycosis usually involves the cervicofacial, thoracic and abdomino-pelvic regions. It is now a relatively rare infection, particularly in the developed world. The pathogenesis is largely unclear. In reviewing the English literature, there were only 154 cases reported over the past 30 years. The most common presentations of thoracic actinomycosis are cough, sputum production and chest pain. Radiographically, it can mimic a wide spectrum of benign and malignant diseases and has the characteristic to penetrate the tissue planes, resulting in abscess or fistula formation.

There were 10 cases of actinomycosis reported in Hong Kong East cluster over the past 10 years and 5 of those cases were treated in Ruttonjee Hospital (Table 1). Penicillin remains the drug of choice for Actinomycosis. IV antibiotics therapy for 2-6 weeks followed by 6-12 months of oral antibiotic therapy is usually recommended for thoracic actinomycosis.


References
  1. Mabeza GF, Macfarlane J. Pulmonary actinomycosis. Eur Respir J. 2003;21:545-551.
  2. Tastepe AI, Ulasan NG, Liman ST, et al. Thoracic actinomycosis. Eur J Cardiothorac Surg. 1998;14:578-583.
  3. Smego RA Jr., Foglia G. Actinomycosis. Clin Infect Dis. 1998;26:1255-1261.
  4. Choi JC, Koh WJ, et al. Optimal Duration of IV and oral antibiotics in treatment of thoracic actinomycosis. Chest. 2005;128:2211-17.
  5. Weese, WC, Smith IM. A study of 57 cases of actinomycosis over a 36 year period. Arch. Intern, Med 1975;135:1562-68.
  6. Conant, EF, Wechsler RJ. Actinomycosis and nocardiosis of the lung. J Thorac Imaging. 1992; 7: 75-84.
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