Septic Arthritis

·   Hot, swollen singular joint

·   Constitutional symptoms (high-grade fever, malaise, weight loss)

Exam:

·   Inability to weight bear

Diagnostic investigation: Joint aspirate

·   Macroscopic: Turbid purulent fluid

·   Microscopic: Elevated WCC with >70% PMN

·   Culture: Positive

·   Severe pain, redness, warmth and swelling usually worst within 12-24h from onset

·   Involvement of first MTP or knee

·   History of self-limiting attacks of arthritis

Exam:

·   Presence of tophi

Diagnostic investigation: Joint fluid aspirate (crystallopathy), MRI

·   Gout: negatively birefringence + yellow needle shape

·   Pseudogout: positively birefringence + rod-shaped

·   Minimal trauma swelling

·   History of coagulopathy

Exam:

·   Hot, swollen joint

·   ± limited range of motion

Diagnostic investigation: Joint fluid aspirate

·   Macroscopic: tinged red

·   Microscopic: xanthochromia

·   Culture: negative

Exam: Pain on active and/or passive movement + limited range of motion

Diagnostic investigation: X-Ray (fracture), MRI (soft-tissue injury)

·   “Morning stiffness” that worsens with immobility

·   Multi-system involvement (fatigue, rash, adenopathy, alopecia, oral ulcers, pleuritic chest pain, Raynaud phenomenon, dry eyes and mouth)

·   Family history of rheumatic diseases

Exam:

·   Eye & skin involvement

·   Joint swelling and deformity (swelling of MCP, swan neck deformity)

Diagnostic investigation: Diagnostic criteria that usually involves clinical, laboratory and imaging results

·   Localised pain or swelling for a few weeks-months

·   Possible noticed following minor trauma

Exam:

·   Distinct soft tissue mass

·   Firmly attached to bone and tender to palpation

Diagnostic investigation: Needle biopsy or operative biopsy

·   Joint pain and stiffness that worsens with mobility but improves with rest

·   History of progressive pain

Exam:

·   Usually involving knees, hips

·   Joint deformity (subluxation of thumb)

Diagnostic investigation: Clinical + X-Ray

If non-severe hypersensitivity to penicillin, cefazolin 2g IV q8hrly

OR depending on local guidelines

Clindamycin 600mg IV q8hly or Lincomycin 600mg IV 8hly

Gram-negative septic arthritis

OR

Cefotaxime 2g (child: 50 mg/kg up to 2 g) intravenously, 8-hourly