Rare Case of Bilateral Orbital Cellulitis in an Adult, Caused by Enterococcus faecalis

Orbital cellulitis is a serious soft tissue infection that involves all orbital contents, including the muscle and fat in this case. In most classifications, it is referred to as post-septal cellulitis; an ophthalmic emergency that may trigger serious loss of vision and even death. The most important distinguishing feature is the fever and inflammatory markers together with presence of ophthalmoplegia and/or proptosis. Although it can occur at any age, it is more common in the paediatric population [1]. Infection is usually caused by Streptococcus pneumoniae, Staphylococcus aureus, Streptococcus pyogenes, and Haemophilus influenzae (more common in children). As a possible cause of orbital cellulitis in immunocompromised patients, invasive aspergillosis and mucormycosis should be considered. Mucormycosis is known to affect patients with diabetic ketoacidosis. Aspergillus-caused orbital cellulitis affects patients with severe neutropenia or other immune deficiencies [2]. Another rare reported cause of orbital cellulitis is Mycobacterium tuberculosis [3]. As seen from the studies mentioned, enterococcal infection is not among the expected orbital infections. It is not only rare but even casuistic.

We report a case of bilateral orbital cellulitis caused by Enterococcus faecalis. The objective of this clinical case report is to highlight this unusual colonization so as to avoid incorrect microbiological diagnosis and non-specific treatment. To the best of our knowledge, only 3 case reports have been published. The treatment is a combination of therapeutic and surgical procedures, multiple imaging controls (MRI, CT, ultrasound) of the state of the drainage and the amount of pus. That motivates us to bring this clinical case to your attention.

A 51-year-old Caucasian man was referred to the ophthalmology department with 1-week history of fever, bilateral painful proptosis, periorbital, lid swelling, and reduced vision. There was inability to open the eyes, sharp retroorbital pain, and discharge. He reported history of sore throat, headache, fever, and malaise a few days prior to eye symptoms. Patient declared no medical history such as hypertension, diabetes, and systemic immunosuppression. He also denied recent trauma, upper respiratory tract infection, insect bite. The patient had been hospitalized elsewhere for 3 days without improvement, and then transferred to the clinic.

Examination revealed bilateral pre-septal orbital oedema as well as overlying redness. Stiff, oedematous eyelids with high temperature and tenderness were observed upon palpation. Inspection further revealed exophthalmos and copious yellow-greenish discharge (Fig. 1). Eye movements were restricted in all directions. Visual acuity of the right eye was 0.15 and that of the left one was 0.04. Anterior segment examination disclosed severe conjunctival chemosis and injection, yellow-greenish discharge, subconjunctival haemorrhage, clear cornea, round and central pupil with limited light reaction. Posterior segment examination revealed oedematous optic disks.

Patient’s temperature was 38°C on admission. His PCR test for SARS-CoV-2 antigen was negative. He was diagnosed with diabetes after a blood glucose profile and started insulin treatment. Consultations were also carried out concerning ENT, immunology, and infectious diseases. On the first day, investigation showed blood glucose 6.48 mmol/L (H), ALAT 66 U/L (H), and C-reactive protein 263 mg/L (H). Total leucocyte count was 17.6 × 10⁹/L (H), erythrocyte count 4.24 × 10¹²/L (L), lymphocytes 8.3% (L), granulocytes 87.8% (H), and haemoglobin 127 g/L (L). Blood and urine cultures were negative.

CT and MRI scan showed bilateral pus collections in the extraconal and intraconal spaces. Diffuse oedema of the periorbital extraocular muscles and soft tissues was also seen (Fig. 2). The CARE Checklist has been completed by the authors for this case report, attached as online supplementary material (for all online suppl. material, see https://doi.org/10.1159/000533608).

The patient was diagnosed with bilateral orbital cellulitis and right temporal abscess. Empirical treatment was started with intramuscular gentamycin (80 mg ×2 daily), intramuscular methylprednisolone (40 mg), intravenous (i.v.) metronidazole (500 mg three times a day), i.v. ceftriaxone (2 mg three times a day), subcutaneous fraxiparin (0.6 mL). Topically, both eyes were infused with tobramycin-dexamethasone drops (5 times a day) and gentamicin ointment (2 times a day). Ringer lactate solution was provided intravenously (30 mL/h). The orbital abscess was drained from all three locations and samples were sent for microbiological examination. Paracetamol (500 mg) was prescribed as required.

A bulge was noted on the right temporal region which upon palpation revealed a build-up of fluid. CT showed soft tissue oedema in the right temporal region. The pus from that region was drained as well. Bilateral orbitotomy was performed and temporal hard drainages were installed.

Microbiology confirmed diagnosis of orbital cellulitis due to Enterococcus faecalis invasion. Sensitivity to ampicillin, gentamycin, linezolid, norfloxacin, vancomycin, and teicoplanin was recorded. On the 8th day, we commenced i.v. ampicillin-sulbactam (Unasyn) 4.5 g and i.v. metronidazole 18 mL (×2 daily) and removed ceftriaxone from the treatment. On 11th day, there was an increase in dose for ampicillin-sulbactam to 7.5 g, and a reduction for gentamicin (80 mg in 2 divided doses).

Two days before the patient’s discharge, investigations showed haemoglobin 136 g/L (N), lymphocyte count 14.8% (L), granulocytes 80.4% (H), RBC 4.7 × 10¹²/L (N) and platelets 376 × 10⁹/L (H). C-reactive protein was 9.3 mg/L (H) and ALAT 73 U/L (H). A day before the discharge, the patient’s fasting glucose was 4.3 mmol/L (N). Visual acuity was 1.0 in the right eye and 0.8 in the left. Inspection revealed a notable reduction in oedema and the ability of the patient to open his eyes and retain his ocular movements (Fig. 3). The patient was discharged with therapy, which included ciprofloxacin 500 mg (×2 a day), chloramphenicol-dexamethasone drops (×5 a day), and dexamethasone-neomycin-polymyxin B ointment (×2 a day).

By the end of the first month, the patient had limited movements of the left bulb (Fig. 4). At the beginning of the third month, visual acuity returned to normal. The face regained its normal appearance (Fig. 5).

E. faecalis is a colonizer in the intestinal tract of mammals and can be found in faeces in large quantities. It occasionally resides in the vagina and the oral cavity but may trigger infections at multiple anatomic sites, such as bacteraemia or catheter-related infections, endocarditis, abdominal and pelvic infections, skin and soft tissue infections among the others.

Our case report seems to be the first published to present bilateral manifestation of orbital cellulitis and abscess, caused by Enterococci in an adult patient. E. faecalis is extremely rare and there are only three published case reports of those we found, all of which are unilateral and the patients are children.

In 1984, Elitsur et al. [4] reported a case of ethmoiditis, conjunctivitis, and orbital cellulitis due to enterococcus infection. This case is similar to ours, in which CT scan showed ethmoidal and sphenoidal sinusitis, too. Sinusitis is an important cause of orbital cellulitis, according to A. Haddadin et al. [5], who examined 25 patients with cellulitis and found out that the most common causative organisms were Streptococcus viridans (44%) and Staphylococcus aureus (32%). Despite Streptococci and Staphylococci being the most frequently encountered in orbital cellulitis, Biedner et al. [6] in 1986 reported a case of Streptococcus faecalis orbital cellulitis. They reported a 2.5-month-old female who was hospitalized with septicaemia, ethmoiditis, and orbital cellulitis and was treated with i.v. ampicillin. Authors conclude that prompt identification of the bacteria is urgent. In 2016, Piyush Kohli and co-authors also reported a case of unilateral Enterococcus faecalis-induced orbital cellulitis and myositis in a 10-year-old Asian Indian child. The CT scan showed a lesion, suggestive of orbital abscess, but, as opposed to our case, there is no evidence of sinusitis [7].

In recent years, it has been proven that Enterococcus is an emerging agent of upper and lower airway diseases, including paranasal sinuses [8]. So, there is a possibility of other cases, caused by E. faecalis to have remained undiagnosed. These cases may have responded quickly to the empiric therapy given, and no abscess may have formed. In our case, the precise treatment was delayed for about 8 days pending the microbiological confirmation of the causative agent.

What remained unclear in our clinical case was the mechanism of infection as well as the relationship between the temporal and orbital abscesses. We were unable to find either anamnestic or etiological data for these two facts. It is unnecessary to speculate about their origin because we could lead the reader to the wrong conclusion.

This is a rare case of bilateral orbital cellulitis and abscesses with invasive E. faecalis infection. E. faecalis infection of the orbit is unusual and should be considered, especially if a patient does not respond to an empiric antibiotic therapy. Abscess drainage materials should be handled properly and microbiological examination should be analysed to identify the causative organism and its antibiotic sensitivity. An adequate diagnosis and prompt intervention and treatment are required to prevent all complications of orbital cellulitis, which are lethal in this case.

The study was conducted in accordance with principles for human experimentation as defined in the Declaration of Helsinki, local Good Clinical Practice guidelines, and local Medical University Pleven institution guidelines. This study protocol was reviewed and approved by the Ethics Committee at Medical University Pleven, approval No. 716-KENID/January 12, 2023. Written informed consent was obtained from the patient for publication of the details of their medical case and any accompanying images.

The authors have no conflicts of interest to declare.

No funding was received.

All authors (G.B., V.I., and Z.B.G.) have made equal contribution to the paper including patient follow-up and article preparation. There are no other parties to acknowledge.

All data generated or analysed during this study are included in this article and its online supplementary material files. Further enquiries can be directed to the corresponding author.