Abscess management

1. POP THAT PIMPLE
ROLE OF ANTIBIOTICS IN ABSCESS
MANAGEMENT

2. • Systematic review 2007
• Studies from RCTs from 1977 and 1982.
• Cohort studies from 2000’s
• Conclusion
Cure rates similar between I+D with antibiotics and I+D
alone.

3. GUIDELINES
Australian
• eTG
I+D alone.
Flucloxacillin if cellulitis
and systemic
symptoms.
USA
• Clinical Practice Guidelines by the
Infectious Diseases Society of
America
I+D is primary treatment.
Antibiotics
>5cm
Cellulitis
Systemic symptoms
Immunosuppression

5. TALAN ET AL.
• 2016
• USA, Multicentre RCT, Double blind
• 1247 patients
• High dose Bactrim (320/1600mg) BD for 7 days versus
placebo.
• Abscesses > 2cm in size.
• Primary outcome was clinical cure at 7-14 days.
• 45% found to be MRSA.

6. TALAN ET AL.
Primary Outcome (ITT)
• Bactrim: 80.5%
• Placebo: 73.6%
Secondary Outcomes
• Subsequent surgical drainage: 3.4% (Bactrim) vs 8.6% (placebo)
• Skin infections at new sites: 3.1% (Bactrim) vs 10.3% (placebo)
• Infections in household members: 1.7% (Bactrim) vs 4.1% (placebo)

7. TALAN ET AL.
Complications
• GIT upset
Bactrim 42% Placebo 37%
• Treatment cessation due to adverse events
Bactrim 1.9% Placebo 0.6%
• No cases of C.Diff

8. Aim: Subgroup analysis for populations guidelines
recommend using antibiotics in.
• >5cm abscess
• cellulitis
• Systemic features
• Immunosuppression (T2DM, CRF)

9. Cure rates higher in all groups treated with Bactrim.
No major difference between
• >5cm and <5cm abscess
• cellulitis >5cm and <5cm diameter
• Immunosuppression (T2DM, CRF)

10. Greatest benefit in
• Subjective symptoms of fevers (16.9%)
• Hx of MRSA (22.9%)
• MRSA grown in culture (20.7%)
(Average improvement 12.2%)

12. DAUM ET AL.
• 2017 USA, Multicentre RCT, Double blind
• 786 patients (Paediatric and Adult)
• 10 days of Bactrim (160/800mg) BD versus clindamycin
(300mg) TDS versus placebo.
• Abscesses <5cm in size.
• Exclusions: obese, multiple lesions, systemically unwell,
major comorbidities (T2DM)
• 49% found to have MRSA.

13. DAUM ET AL.
Primary outcome: clinical cure rates at 19-22 days
• Clindamycin 83.1%
• Bactrim 81.7%
• Placebo 68.9%

14. DAUM ET AL.
Treatment associated adverse events
Clindamycin 21% Bactrim 11% Placebo 12%
• No cases of C.Diff
• 1 hypersensitivity reaction to Bactrim
Fever, rash, thrombocytopenia, hepatitis (self
limiting)

15. • Systematic review and meta-analysis of RCTs.
• 2406 patients.
• 4 studies.

16. Treatment failures
• Antibiotics 7.7% Placebo 16.1%
• NNT 13.5
Lesions at other sites
• Antibiotics 6.2% Placebo 15.3%
• NNT 11

17. Adverse events
• Antibiotics 24.8% Placebo 22.2%
• NNH 23

19. ISSUES
• US studies only.
• Significant amounts of overlying cellulitis in study
populations.
• Rare but serious drug side effects associated with
Bactrim and clindamycin (C. Diff, SJS).
• Changes to resistance patterns of Staph Aureus with
widespread antibiotic use.
• Which drug and what dose?