Sir,

A 78-year-old man, with aortic valve replacement, presented with deteriorating right vision, pyrexia, and weight loss following dental extraction. Actinobacillus actinomycetemcomitans, a slow growing, Gram negative ‘HACEK’ bacterium was grown from blood cultures and a concomitant, intertarsal abscess. Positive HACEK cultures from metastatic, abscesses are previously unreported.

Case report

A 78-year-old Caucasian male presented with a 3-week history of a tender, inflamed right eye with deteriorating vision. Following premolar extraction a year earlier fever, night sweats, and weight loss were reported.

Previous medical history included IDDM and rheumatoid arthritis. Twelve years earlier, the patient had undergone an aortic valve replacement. Drug history included prednisolone and methotrexate for inflammatory arthritis. Furthermore, an erythematous, area of skin on the dorsum of the right foot was noted (Figure 1).

Figure 1
figure 1

Photograph of right foot before intertarsal abscess debridement

Full size image

On examination, visual acuity was ‘hand movements’ only in the right eye and 6/9 in the left eye. Right anterior segment revealed injection, anterior chamber cells (3+), a 1 mm hypopyon, posterior synechiae with fibrin and lenticular nuclear sclerosis. There was a dense vitritis confirmed with ultrasound examination. The left eye was unremarkable. Normal urinalysis and chest X-ray were reported.

Blood cultures were obtained on admission and anterior tap and undiluted vitreous specimens were obtained for microbiological investigation. Intravitreal vancomycin (1 mg in 0.1 ml) and ceftazidime (2.0 mg in 0.1 ml) were administered.

The patient's presumed right, pedal cellulitis was treated with oral penicillin and flucloxacillin. Echocardiograms were negative. Antibiotics were stopped and on the 12th postoperative day, the cultured blood specimens revealed Gram negative cocco bacilli consistent with HACEK (Haemophilus sp. (parainfluenzae, aphrophilus, paraphrophilus), A. actinomycetemcomitans, Cardiobacterium hominis, Eikenella corodens, and Kingella kingae) infection. Treatment with intravenous gentamycin and amoxicillin was commenced. A week later, the right foot lesion was debrided to reveal an intertarsal abscess and pus collected grew A. actinomycetemcomitans. The abscess healed well following debridement.

Comment

The HACEK group of organisms is an unusual cause of infective endocarditis, responsible for 3% of cases.1 Of the five reported cases of endogenous endophthalmitis due to A. actinomycetemcomitans, four had pre-existing heart abnormalities, three had permanent pacemakers, and two had periodontal disease.2, 3, 4, 5, 6

Our case describes this unusual cause of metastatic endophthalmitis, secondary to endocarditis, with concomitant foot abscess. There are no previous reports of macroembolic, metastatic, abscesses requiring debridement and growing positive cultures for A. actinomycetemcomitans. Poor glycaemic control and immunosuppression may have contributed to these novel manifestations.