Arthritis, Septic (Pyogenic)

Description

Diagnostic criteria

General and supportive measures

Medicine treatment

Referral

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ICD-10 code: M00.9

DESCRIPTION

Septic arthritis may occur as a result of haematogenous seeding of the synovium during transient periods of bacteraemia.
Septic or pyogenic arthritis is often part of a generalised septicaemia which may involve more than one joint and is caused by pyogenic micro-organisms.

The organisms involved vary:

• Neonates – S. aureus, Group B Streptococci, E. coli, fungi.
• Infants/children – S. aureus, H. influenzae, Group A Streptococci, S. pneumoniae, Kingella kingae.
• Adolescents (sexually active) – N. gonorrhoea.
• Chronic septic arthritis – Brucella, tuberculosis, atypical mycobacteria, fungi and other uncommon organisms.

DIAGNOSTIC CRITERIA

The diagnosis is largely clinical and confirmed by finding pus in the joint space.

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CAUTION:
Do not carry out needle aspiration in haemophiliacs.

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Clinical

• Fever, local pain, loss of function and toxic looking child.
• Subtle, non-specific signs of sepsis early in the course of the disease, especially in neonates.
• Local tenderness, warmth, swelling at a joint with restriction of passive and active movement.
• Malaise, irritability, feeding problems and pseudo-paralysis.
• If lower extremities are involved, development of a limp or refusal to bear weight.

Investigations

• Blood cultures prior to antibiotic administration.
• Aspiration of pus from the joint space under ultrasound guidance, if possible, and submit for microscopy, Gram stain, culture and sensitivity.
• Raised CRP and white cell count and/or ESR.

GENERAL AND SUPPORTIVE MEASURES

• Septic arthritis of the hip (emergency) requires prompt open surgical drainage at the time of presentation, in consultation with an orthopaedic surgeon.
• Manage most infections of other sites by repeated aspiration or open drainage (not antibiotic instillation), if frank pus is obtained on initial diagnostic aspiration.
• Immobilise affected limb in position of function.
• Identify other effects of septicaemia or haematogenous spread and treat appropriately.
• Supportive and symptomatic care.

MEDICINE TREATMENT

Antibiotic therapy

• Minimum duration of therapy: 4–6 weeks.

IV antibiotics

Initiate IV antibiotic treatment immediately.

Adjust antibiotic therapy based on culture results or if response to empiric antibiotic treatment is unsatisfactory.

Continue with IV antibiotics until there is evidence of good clinical response and laboratory markers of infection improve. Once clinical improvement and inflammatory markers are normalising, patients can be switched to oral antibiotic therapy.

Neonates:

• Cloxacillin, IV, 50 mg/kg/dose.
  • If 1^st week of life: 12 hourly.
  • If 2^nd–4^th week of life: 8 hourly.
  • If > 4 weeks old: 6 hourly.

PLUS

• Cefotaxime, IV.

Gestational age	Postnatal age	Dose
< 32 weeks	< 14 days	50 mg/kg/dose every 12 hours
	14–28 days	50 mg/kg/dose every 8 hours
≥ 32 weeks	≤ 7 days	50 mg/kg/dose every 12 hours
	8–28 days	50 mg/kg/dose every 8 hours

1 month to < 3 months:

• Cloxacillin, IV, 50 mg/kg/dose 6 hourly.

PLUS

• Ceftriaxone, IV, 100 mg/kg, once daily.

Infants > 3 months and children:

• Cloxacillin, IV, 50 mg/kg/dose 6 hourly.

If gram-negative organisms are seen on Gram stain, or when clinically suspected, e.g. sickle cell disease:

ADD

• Ceftriaxone, IV, 100 mg/kg, once daily.

Special Circumstances

If MRSA, replace cloxacillin with vancomycin.

• Vancomycin IV, 15 mg/kg/dose administered over 1 hour given 6 hourly.
  • Where available, vancomycin doses should be adjusted on the basis of therapeutic drug levels.
    • Trough levels (taken immediately prior to next dose), target plasma level 15–20 μg/mL.

Oral antibiotics

• Can transition to oral therapy once there is sustained clinical improvement, resolution of fever and CRP < 30 mg/L.
  • Duration: 2–4 weeks of treatment.

Antibiotics according to sensitivities:

• Clindamycin, oral, 6 mg/kg/dose 6 hourly.

OR

For children able to swallow a capsule:

• Flucloxacillin, oral, 12.5–25 mg/kg/dose, 6 hourly.

PLUS

Corticosteroids

• Dexamethasone, IV, 0.15 mg/kg 6 hourly for 4 days.

LoE I³

For pain and inflammation:

See: Pain control.

REFERRAL 

• Multi-organ involvement.
• Failure to achieve progressive improvement on treatment.
• Rehabilative care including occupational and physiotherapy.

Click here for the pdf.

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Standard Treatment Guidelines and Essential Medicines List for South Africa Paediatric Hospital _2023, 5th edition_Updated July 2024 

Chapter 8: Infective/Infectious Diseases,  8.29 Arthritis, Septic (Pyogenic)