Neck Mass in a Returning Traveler FREE

A 49-year-old man with a history of diabetes presents to the emergency department of a US hospital with an abdominal wall abscess. He recently completed a summer pilgrimage to Bangladesh and Saudi Arabia. Incision and drainage are performed but no cultures are sent. He is given empirical double-strength trimethoprim-sulfamethoxazole twice daily for 14 days. Several weeks later he returns with painful swelling of the left side of his neck associated with subjective fever and chills. On examination he is afebrile and a tender, 2-cm fluctuant neck mass is palpated. A contrast computed tomography (CT) scan of the neck is performed (Figure 1). The patient is given oral clindamycin with plans for ultrasound-guided incision and drainage by an otorhinolaryngologist. However, after 8 days of empirical clindamycin, he returns to the emergency department with worsening neck pain. He is afebrile and no laboratory abnormalities are noted except for an elevated glucose level of 335 mg/dL.

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Soft tissue melioidosis

A. Admit patient to the hospital for surgical drainage of the mass and send samples for appropriate stains, culture, and cytology

The key feature highlighted by this case is the lack of improvement after a reasonable duration of empirical antibiotics in a returning traveler with uncontrolled diabetes. His worsening symptoms suggest that the mass is either due to a pathogen not covered by clindamycin or is noninfectious. Surgical drainage with samples sent for stains, culture, and cytology would be the best next step.

Burkholderia pseudomallei (melioidosis) is a soil- and water-dwelling aerobic, gram-negative bacillus endemic to Australia and Southeast Asia. It commonly causes musculoskeletal infections and community-acquired pneumonia and is an important cause of sepsis in endemic regions. Clinical manifestations range from indolent, chronic infections to fulminant sepsis.¹ Mortality due to disseminated melioidosis reaches 50% in some regions.² Melioidosis typically causes abscesses in the lungs, skeletal muscle, and visceral organs but rarely in soft tissue.³ Risk factors for disseminated disease include diabetes and chronic renal insufficiency.⁴

Although it is a well-recognized cause of disease in some tropical regions, melioidosis is rarely seen in the United States, where the diagnosis may be missed or delayed due to low clinical suspicion compounded by the unfamiliarity of many US clinical laboratories with B pseudomallei. Diagnosis requires positive cultures from an infected site.

Treatment with ceftazidime or meropenem for 14 days followed by high-dose trimethoprim-sulfamethoxazole, doxycycline, and/or amoxicillin-clavulanate for up to 6 months is required.⁴ Continuing clindamycin in a patient with worsening symptoms would not be appropriate (answer C). Broadening antibiotic therapy would not be a sufficient stand-alone approach (answer B). There is no indication for intubation (answer D).

Cytologic examination of the abscess fluid showed degenerated epithelial cells in a background of marked, acute inflammation and cell debris without evidence of malignancy. Blood cultures were negative. Gram stain and acid fast bacilli stain were negative. Burkholderia pseudomallei was ultimately grown in culture from the abscess fluid and confirmed by molecular analysis (Figure 2).

The patient was treated with intravenous meropenem for 14 days followed by high-dose trimethoprim-sulfamethoxazole for 6 months. He was followed up by infectious disease physicians as an outpatient and his symptoms continued to improve. Diabetes control was emphasized and his metformin dosage was increased. Given the concern that the initial abdominal abscess represented soft tissue melioidosis, CT imaging of his chest, abdomen, and pelvis was performed to rule out disseminated disease; results of these studies were negative.

Identifying melioidosis in nonendemic regions requires a high level of suspicion, careful attention to risk factors such as travel history and comorbidities, and notification of the laboratory that the infection is suspected. It is critical that physicians remain vigilant in an era when international travel blurs the borders between endemic and nonendemic locations.