18th January 2024

A 38-year-old lady has been referred to Rheumatology for a possible diagnosis of RA.

A 38-year-old lady has been referred to Rheumatology for a possible diagnosis of RA. She now presents to A &E with a 3-day history of right knee pain and swelling. She initially thought this was related to the possible underlying diagnosis of RA, so took regular analgesia but has had to attend today as she has been lethargic, has had fevers and is vomiting. On examination, her temperature is 37.9 degrees. The skin around the knee does not look infected, but it is red, warm to touch and swollen. Flexion and extension of the knee is restricted. 

Preliminary investigations are as follows:

Hb 115 g/L (115-165)

MCV 82.5fL (80-96)

WCC 15.0  x 10*9/L (4.0-11.0)

CRP 80 mg/L (<10)

What is the next best management option?

Select the SINGLE most appropriate option from the list below. Select ONE option only.