Caleb Ward, Children’s National Medical Center
with Asha Payne, Children’s National Medical Center

The Case
A 3yo M presented with fever and a swollen knee, with a story and lab results most consistent with Lyme arthritis. This case focused on risk aversion among providers, asking them how they would manage a patient for whom septic arthritis was a possible, albeit unlikely, diagnosis.

Here’s How You Answered Our Questions

Of note, experience seemed to make our respondents a bit more cavalier. Attendings who voted were less likely than fellows to sedate the patient for the tap. They were also less likely to admit him for observation on antibiotics.

Denouement:
The ED team performed the joint aspiration after administration of intranasal fentanyl. Orthopedics was consulted and agreed that the clinical picture and initial aspirate results were less concerning for a septic joint. The patient was admitted to the hospitalist service. ID was consulted and agreed that his clinical picture was most consistent with Lyme disease, and he was started on a 28 day course of Amoxicillin. No further imaging was performed. His rapid strep test was negative. Blood culture was sterile. The Lyme serology that was sent was never tested due to lab error. The joint aspirate culture only grew contaminants. His Lyme IgG was positive at his first ID clinic follow up, supporting the diagnosis of Lyme arthritis. Almost one month later at follow up in ID clinic he had almost normal gait and was afebrile, but still had a significant effusion. He continues to follow up to determine need for possible extension of his antibiotic course.

Dewesh, Asha, and Maybelle left a few very insightful comments.