Acute infection of a single joint (usually a large joint), commonly affecting children.


  • Usually haematologenous spread from a primary focus following bacteraemia (e.g. septic skin lesions, sinus
    infections, throat infections, abrasions, wounds, pressure sores, and osteomyelitis)
  • Commonly involved in acute arthritis: Staphylococcus aureus and Gram negative bacilli, e.g., Salmonella spp,
    Streptococcus spp, Gonococcus
  • In chronic septic arthritis: Brucella, tuberculosis

Clinical features

  • Swollen and warm joint
  • Severe pain, reduced or abolished movement, temporary loss of limb function (pseudoparalysis)
  • Localised heat and tenderness
  • Systemic symptoms: fever (neonates may not show fever but refuse to feed), general malaise
  • Complications: irreversible joint damage if immediate treatment is not established

Differential diagnosis

  • Inflammatory joint disease
  • Intra-articular haemorrhage, e.g., haemophilia and other bleeding disorders
  • Trauma
  • Osteomyelitis of neighbouring bone


  • Blood: Full blood count, C&S, ESR (usually elevated)
  • Joint fluid: Aspirate for C&S; in case of failure to get pus by aspiration, use arthrotomy (in theatre)
  • Joint fluid: Gram stain


  • Provide pain relief, e.g., paracetamol, or ibuprofen
  • Immobilise the involved limb, try splinting
  • Aspirate articular fluid for gram stain, and C&S if available (use local skin and subcutaneous
    anaesthesia if indicated)

    • Repeat daily until no further pus is obtained
    • Use diazepam 2.5 mg rectal for sedation in children
  • Or open drainage in theatre
  • Continue pain relief, use paracetamol, ibuprofen
    • Or diclofenac 50 mg every 8 hours Child: 0.3-2 mg/kg rectally every 6-8 hours (max 150 mg)
    • Or indomethacin 25-50 mg every 8 hours Child: 0.5-1 mg/kg every 12 hours

Antibiotics: if possible, get guidance from gram stain, and culture and sensitivity results

If Gram positive at gram stain, or negative stain but immunocompetent adult patient:

  • Cloxacillin 500-1 g IV every 6 hours Child: 50 mg/kg IV every 6 hours
    • Give IV for 2 weeks, then if better, switch to oral to complete 4 weeks
  • Alternative/second line: Chloramphenicol 500 mg IV every 6 hours for at least 2 weeks Child: 12.5
    mg every 6 hours

If Gram negative at gram stain

  • Ceftriaxone 1 g IV for 2-4 weeks


  • Ciprofloxacin 500 mg every 12 hours for 3 weeks

In adults with negative stain and underlying conditions (suspect gram negative, e.g. Salmonella
in Sickle Cell Disease), and all children with negative stain, or underlying conditions

  • Cloxacillin + ceftriaxone

If suspicion of gonococcal (e.g. in sexually active adolescents)

  • Ceftriaxone 1 g IV daily for 1 week