Orbital and Pulmonary Actinomycosis: The First Case Report and Literature Review

Orbital actinomycosis is a very rare clinical manifestation of orbital infection caused by Actinomyces species, anaerobic Gram-positive filamentous bacteria. We report herein a case of a 58-year-old man who presented with chronic progressive course of total ophthalmoparesis in association with productive cough, leading to the diagnosis after extensive investigation. In addition, all reported cases of orbital actinomycosis in the literature are reviewed.


Introduction
Actinomyces species are anaerobic Gram-positive filamentous bacteria and ubiquitous in soil and microbiota of both animals and humans. e infection caused by Actinomyces species, actinomycosis, is usually indolent and slowly progressive [1]. ere are wide clinical manifestations of actinomycosis depending on the infection site including orocervicofacial, thoracic, abdominal, and pelvic diseases [1]. To date, there have been handful cases of orbital actinomycosis. e source of infection is usually following the head injury or from the infection of adjacent paraorbital organs including paranasal sinus, nose, cavernous sinus, and brain. We report herein a case of a 58-year-old man who presented with chronic progressive course of total ophthalmoparesis in association with productive cough, leading to the diagnosis after extensive investigation.

Case Report
A 58-year-old ai previously healthy male farmer, living in Roi Et Province (Northeast ailand), was referred to our hospital, King Chulalongkorn Memorial Hospital, due to problems with total ophthalmoparesis and productive cough for 2 months. Two months prior to admission (PTA), he developed productive cough and low-grade fever with no response to many courses of antibiotic treatment. One month PTA, he noted binocular horizontal diplopia of the right eye, before progression to visual loss and ptosis despite antibiotic and steroid treatment. His past medical history was unremarkable except heavy alcoholic drinking. e right eye examination revealed eyelid swelling, proptosis, marked chemosis, and complete ptosis; light perception of visual acuity; absent afferent pupillary reflex; and optic disk swelling and retinal hemorrhage. Neurological examination revealed right eye total ophthalmoparesis and decreased pinprick sensation of right cranial VI nerve area. Multiple dental caries were noted. Pulmonary examination revealed fine crackles at both the lungs. Other examination was unremarkable.
Complete blood count showed hemoglobin of 9.3 g/dL, white blood cells of 25,540 cells/mm 3 (85.1% neutrophil, 9.8% lymphocyte, and 4.8% monocyte), and platelets of 697,000 cells/mm 3 . Blood chemistry was normal. Anti-HIV test was negative. Chest X-ray revealed bilateral diffuse reticulonodular and alveolar infiltrations. Orbital computed tomography revealed a 1.5 × 2.9 × 1.5 cm rim-enhancing hypodense lesion at the right orbital apex abutting to the optic nerve sheath complex and right medial rectus muscle ( Figure 1).
A diagnosis of orbital and pulmonary infections was made, and emergent anterior orbitotomy was performed and revealed purulent discharge from the orbit. e pus and sputum Gram stain exhibited many Gram-positive filamentous bacilli, but non-acid-fast, on both standard and modified acid-fast bacilli stains. Hence, Actinomyces species was suspected, and Nocardia species could be excluded due to negative results on modified AFB stain. e pus cultures finally grew Actinomyces israelii (Figures 2(a) and 2(b)). Further bacterial identification by base sequencing of 16S ribosomal DNA was A. israelii with 99% identity (NCBI BLAST Search).
He was given penicillin G sodium of 24 million units per day for 6 weeks and amoxicillin of 2 g per day for another 12 months. After 10 days of treatment, there was a much improvement of lung infiltrates on his chest X-ray. e patient was doing well when last seen 1 year after discharge with mild residual impaired ophthalmoparesis and ptosis but still moderate visual impairment.

Discussion
To our knowledge, our case is the first report of both orbital and pulmonary actinomycosis. All previously reported cases were only orbital actinomycosis.
A portal of entry to the orbit in our case is probably from the hematogenous spread from the lungs, even though only unilateral orbit is involved. Due to sequence of respiratory and eye symptoms, the imaging reveals that there is no infection of paraorbital organs and presumed aspiration pneumonia from heavy alcohol drinking. In contrast, orbital actinomycosis in all previously reported cases was caused by infection in paraorbital organs or following the injury.

Conclusions
To our knowledge, our case is the first report of both orbital and pulmonary actinomycosis, likely from hematogenous spread from the lungs.