Dare to pass a needle into this potentially aseptic red, swollen joint? Dare to miss a septic arthritis? Red, swollen knees come in a variety of flavors. How does the astute clinician distill which knees need taps, and which don’t? Let’s walk through the broad differential, and review strategies and literature to develop a safe approach to minimize missing detrimental diagnoses in the presentation of a red, swollen knee.
