An unusual case of orbital cellulitis due to Panton Valentine Leucocidine producing Staphylococcus aureus

Sir,

We report an unusual case of orbital cellulitis due to Panton Valentine Leucocidin (PVL) producing Staphylococcus aureus bacteraemia secondary to a furuncle. Both the orbital cellulitis and the secondary pulmonary involvement resolved completely with linezolid and clindamycin.

Case report

A 68-year-old Asian male presented with rapid onset right upper lid swelling, redness and pain. The symptoms started 24 h after a small boil on the tip of his nose and then progressed to a full blown orbital cellulitis the next day. He had poorly controlled type 2 diabetes mellitus (HbA1c 6.9). On examination visual acuity was light perception and he had axial proptosis, a very tense orbit, severe chemosis and ophthalmoplegia (Figure 1). He was apyrexial and did not have any known immune deficiency or compromise. Blood culture was taken and intravenous flucloxacillin, ceftriaxone and metronidazole were administered.

Figure 1.

(a) A photo of the patient. (b) Axial CT scan of the orbit, showing several patchy areas of inflammatory change within the cone area.

After 48 h of treatment there was no clinical improvement. He developed pleural effusion (Figure 2). Results of blood culture yielded PVL-positive Staphylococcus aureus with leukocytosis of 40 000 cells/ml and CRP was 187 mg/l. Treatment was switched to Linezolid and clindamycin. Pulmonary involvement and orbital cellulitis resolved after a 2-week course of new regime.

Figure 2.

The pulmonary CT angiogram shows left-sided dependent pleural effusion and a greater right-sided loculated effusion with a paraspinal pleural collection.

Comment

Orbital cellulitis is potentially a life- and sight-threatening condition needing immediate ophthalmology/ENT management. In 90% of cases, orbital cellulitis is secondary to sinusitis. In small number of patients, bacteraemia is the culprit. Reports suggest Staphylococcus species are increasingly becoming resistant to methicilin both nosocomial and community-acquired infections (CA-MRSA). A recent study from the National Health and Nutrition Examination Survey found the incidence of S. aureus colonization in the US population to be 31.6% and the incidence of MRSA carriers to be 0.84%.¹ Mathias et al² showed that orbital cellulitis is preceded by boil/chalazia in CA-MRSA cases. CA-MRSA carrys PVL gene, which is a cytotoxin that destroys cells.³ Several studies suggest that CA-MRSA is an important emerging cause of orbital cellulitis.⁴ Our case is unusual because the patient developed not only fulminant orbital cellulitis following a CA-MRSA skin infection but also secondary pleural effusion.

We believe in cases of orbital cellulitis not responding to conventional antibiotic regime, clinicians should consider the possibility of infection from PVL producing Staphylococcus aureus and institute appropriate treatment.

The authors declare no conflict of interest.