الرثوية

A 22-year-old woman living in Massachusetts is evaluated for a 4-day history of multiple “bug bites” and left ankle pain. Her symptoms initially presented with painful, nonpruritic welts on her legs and severe left ankle pain 4 days after mowing her lawn. She has been walking with a limp.

On physical examination, temperature is 38.2 °C (100.8 °F). The left ankle is slightly swollen. On musculoskeletal examination, passive motion of the left ankle elicits pain. Her skin lesions are shown and are tender to palpation.

On laboratory studies, complete blood count, serum chemistry studies, and urinalysis are normal. Arthrocentesis of the left ankle yields 1.5 mL of fluid (leukocyte count, 4,000/µL [4 × 109/L]; 45% neutrophils). Polarized light microscopy shows no crystals. Culture results are pending.