Red 2

A 50 year old postmenopausal woman presents with a red, swollen left knee which is painful to touch.

There was no history of fever, rash, diarrhea, uveitis, prior knee swelling, antecedent trauma, knee surgery, or risky sexual behavior.

She was diagnosed with rheumatoid arthritis 2 years ago, and is on long-term low dose corticosteroid therapy.

Select Relevant Investigations


WBC 50,000/mm3 (<200)
Polymorphs: >50% (<25%)
Gram stain: multiple gram positive cocci noted
Cultures: will be available in 3 days
Crystals: negative
Full Blood Count


WBC: 9,500/ mm3 (4,000 - 10,000/mm3)
N: 93%, L: 5%
Hb: 12.3 g/dL (11.5 - 17.5)
Platelets: 320,000/mm3 (150,000-450,000)
Blood Cultures


Gram Stain: Multiple gram positive cocci are noted
Culture reports will be available in 3 days.
X ray L/Knee


There is widening of the joint space suggestive of a moderate effusion. There is no evidence of joint destruction.

Select Relevant Management
IV Antibiotics
Stop Corticosteroids
Immobilize joint
Joint drainage