A 29-year-old male presents to the office with the complaint of bilateral knee pain. History reveals the patient is a park ranger at Niagara Falls and noticed a small target-like rash in his armpit a few weeks ago. He states the knee pain has been worsening over the last few weeks and he has also been experiencing more fatigue than usual. Vital signs reveal show a temperature of 37.1ºC (98.8ºF), a blood pressure of 116/74 mmHg, a heart rate of 68/min, and a respiratory rate of 14/min. Physical examination reveals a mild effusion and erythema in both knees. Range of motion is within normal limits and McMurray and Apley tests are negative. There is no ligamentous laxity.
The best initial test is?
- blood culture
- drug screen
- enzyme linked immunosorbent assay
- urinary antigen testing
- western blot
The initial test is found to be positive. The test to confirm the diagnosis is?
- blood culture
- drug screen
- enzyme linked immunosorbent assay
- no further testing is necessary
- western blot