Septic Arthritis and Concern for Osteomyelitis in a Child with Rat Bite Fever

Abstract

bRat bite fever is a rare infection usually caused by Streptobacillus moniliformis. A case of septic arthritis and possible osteomyelitis as sequelae of rat bite fever in a pediatric patient is described. CASE REPORTA 22-month-old male presented during the summer of 2011 to the emergency department of the Alfred I. duPont Hospital for Children with 2 days of upper respiratory tract symptoms followed by 5 days of fever, malaise, and a gradually worsening rash on his upper and lower extremities, including his palms and soles. The rash began to blister, and the toddler became irritable, prompting evaluation. Given his prodrome and rash, the patient was initially thought to have a viral syndrome, such as coxsackievirus. He was admitted for intravenous hydration and pain control. Initial vital signs included mild hypertension, tachycardia, and a fever to 38.0°C.Physical examination revealed a toddler in moderate distress with a tender, erythematous, pustular rash scattered on his feet (Fig. 1), ankles, and hands. No joint swelling or tenderness was initially noted; however, due to patient anxiety, examination was difficult. Initial laboratory results were unremarkable, including a white blood cell (WBC) count of 10,200/l, a hemoglobin concentration of 10.9 g/dl, and a platelet count of 217,000/l, with normal differential values, electrolytes, and urinalysis results. Blood and left-foot pustule fluid were sent for cultures. Over the next few days, his fevers persisted in the setting of a worsening rash and pain. The patient had reportedly been walking less prior to admission, which was attributed to the painful lesions on his feet, but on day 5, he refused to bear any weight and on exam was noted to have pain when his right-hip range of motion was examined. Repeat blood work revealed a WBC count of 18,100/l, a hemoglobin concentration of 10.0 g/dl, a platelet count of 523,000/l, and a neutrophilic predominance. Inflammatory markers revealed a C-reactive protein concentration of 5.4 mg/dl and an erythrocyte sedimentation rate of 94 mm/h. A repeat blood culture was drawn, a lumbar puncture was performed, and an infectious disease specialist was consulted for further evaluation. An ultrasound of the right hip was performed, which found a joint effusion, and the child was started on vancomycin and ceftriaxone for empirical bacterial coverage. Caretakers rereviewed the patient's initial history, and a physical and further discussion revealed that the family had two pet rats. Rat bite fever (RBF) quickly entered the differential.The patient was taken emergently to the operating room due to concern for septic joint, where right-hip joint aspiration revealed a cloudy, green fluid, which was sent for a cell count and culture. Given the clinical scenario and appearance of the fluid, formal open irrigation and debridement of the joint were performed. After 6 liters of irrigation, a sterile Jamshidi needle was used to aspirate the proximal metaphysis of the right femur, and the bone sample was sent for culture. The Gram stain of ...

A case of rat bite fever in a 12‐year‐old boy

“…The course was uncomplicated, possibly as a result of early antibiotic treatment in response to the positive blood culture. Reported severe complications include endocarditis, meningitis, septic arthritis and multi‐system involvement, which may reflect disseminated infection …”

The Brief Case: Rat Bite Fever from a Kiss

“…Pediatric BD Bactec Peds Plus/F (BD) blood culture bottles likely contain less SPS (0.02% [wt/vol]) than the nonpediatric bottles. Description of the type of blood bottle used in pediatric cases of S. moniliformis has often not been provided in the published literature; thus, success of recovery with pediatric blood culture bottles is unknown (10,11). Recovery of S. moniliformis can be achieved on media containing blood incubated in 5 to 10% CO 2 at 37°C (1,3).…”

Streptobacillus moniliformis bacteremia in a rheumatoid arthritis patient without a rat bite: a case report

“…Disease caused by S. minus is generally known as Sodoku and occurs primarily in Asia [ 2 ]. After the incubation period of 2–10 days, symptoms progress to high fever, arthralgia of multiple joints, muscle ache, and whole body rash [ 1 , 13 – 16 ]. In previous reports, arthritis occurred mainly in large joints including the elbows, knees and mid-back, while rashes of the palms or soles and were erythematous [ 3 , 13 , 14 , 16 – 19 ].…”