Sir,

Septic metastatic endophthalmitis is a rapidly devastating ocular infection resulting from the haematogenous spread of organisms to the eye. Several studies have shown diabetes mellitus to be the most common association, especially in patients with liver abscess.1, 2 Other primary foci of infection include urinary tract infection, pneumonia, peritonitis, and meningitis. This report describes a case of septic metastatic endophthalmitis resulting from the rare foci of infection — scalp furuncle.

Case report

A 74-year-old non-insulin-dependent diabetic woman was admitted to our hospital because of fever, headache, and scalp furuncle. One week before admission, she had a motorcycle accident and sustained minor abrasions to the left scalp. She was otherwise asymptomatic and povidone iodine ointment was requested four times per day. In the subsequent days, the abrasion wound became worsening and accompanied with severe tender, swelling, and pus formation. We considered the diagnosis of scalp cellulitis. The patient was then treated with empiric parenteral oxacillin and gentamycin while awaiting wound and blood cultures.

One day after admission, she complained of left eye pain and visual loss. Her ocular history was insignificant, except for senile cataract in both eyes. The initial ocular examination (2 days after admission) revealed a best-corrected visual acuity of counting fingers in the left eye. Swollen eyelid, severe chemosis, conjunctival injection, corneal oedema, and hypopyon were observed in her left eye (Figure 1). The diagnosis of septic metastatic endophthalmitis was suspected. Immediate pars plana vitrectomy (2 days after admission) was performed followed by intravitreal vancomycin (2 mg/0.1 ml) and ceftazidime (2 mg/0.1 ml). Topic fortified vancomycin and amikacin eye drops were also given. Cultures from blood, scalp furuncle, and vitreous all grew Klebsiella pneumoniae, which was sensitive to ceftriaxone, ceftazidime, gentamycin, and amikacin, and resistant to oxacillin. The parenteral oxacillin was then replaced by ceftriaxone (2 g/day) and vancomycin eye drop was also changed to ceftazidime. The debridement of the scalp furuncle was performed (Figure 2). After 3 weeks, endophthalmitis subsided without visual recovery.

Figure 1
figure 1

Photograph of her left eye 2 days after admission, showing swollen eyelid, severe chemosis, conjunctival injection, corneal oedema, and hypopyon.

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Figure 2
figure 2

After debridement of scalp furuncle, a large skin defect and deeply open wound were noted. Exopthalmos with swollen eyelid were also noted in her left eye.

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Comment

Septic metastatic endophthalmitis is a rare entity that accounts for 2–15% of all endophthalmitis, which itself occurs at an average annual incidence of about five in 100 000 hospital patients.3 Several studies have shown diabetes mellitus to be the most common association. However, several patients had unrecognised diabetes or diabetic infection before endophthalmitis onset. The early diagnosis is often difficult, particularly when there is no evidence of a primary infection. In fact, the ocular infection can be the initial manifestation of sepsis. In addition, the visual outcome of septic metastatic endophthalmitis caused by K. pneumoniae was worse than counting fingers in more than 80% of patients with affected eyes in most series.3, 4, 5 Therefore, more aggressive treatment may be needed. In our patient, although the primary focus of infection was obvious and urgent treatment was also given, the visual prognosis is still disappointed.

In the past, septic metastatic endophthalmitis caused by K. pneumoniae was considered to be rare. Before 1980, only one patient was reported in the literature.6 However since 1981, more than 40 cases have been described, mainly in Taiwan, with 61% diabetes mellitus, 68% of patients having suppurative liver disease, and 16% having urinary tract infection as the primary focus of infection.7 To date, the primary foci from skin infection was only noted in three patients. Okada et al2 reported two cases of septic metastatic endophthalmitis from skin cellulitis. One resulted from skin burn with Staphylococcus aureus infection and another was skin abscess owing to intravenous drug abuse, in which the infectious organism was not identified. However they did not mention whether these patients were diabetic mellitus. Wong et al8 reported one diabetic patient of septic metastatic endophthalmitis from foot abscess with S. aureus infection. Therefore, to the best of our knowledge, this is the first case of septic metastatic endophthalmitis resulting from scalp furuncle with K. pneumoniae infection described in diabetic patient.

In conclusion, the physician must take into account that diabetic patients could have a metastatic infection to eyes when with skin infection.