Cellulitis Treatment

(NEJM 2014;370:2238; CID 2014;59:e10; JAMA 2016;316:325 & 2017;317:2088) | Purulent | Usual Micro | Severity | Treatment |

No Purulent

• Necrotizing Infection / Cellulitis / Erysipelas β-hemolytic Strep >S. aureus

Mild: Oral: PCN VK, cephalosporin, Dicloxacillin, Clindamycin

Mod: IV: PCN, ceftriaxone, cefazolin, Clindamycin

Severe: IV: vanc + pip/tazo (± clinda for toxic shock syndrome)

嚴重的感染，要早點確定診斷，要排除不是Necrotizing Fasciitis

• Monomicrobial (嘴炮時間：根據2014 IDSA guideline non-purulent cellulitis，嚴重感染常見的病原菌有Strep pyogenes, Clostridial, Vibrio…，首選的治療主要是Penicillin加上Clinda，另外的選項也有Doxycycline, Ceftz, Cipro)
  • Strep pyogenes
  • Clostridial sp.
  • Vibrio vulnificus
  • Aeromonas hydrophila qv: 熱病 Acute bacterial skin and skin structure infections

Yes Purulent

如果已經有膿，這時我不會把診斷叫cellulitis，要叫furnucle, carbuncle, abscess

S. aureus (incl. MRSA) >> β-hemolytic Strep

會造成這樣嚴重的感染，最需要排除的就是MRSA，同時一定要找整外評估，看是否要做切開流

Mild: Consider I&D only vs. I&D + clinda or TMP-SMX (NEJM 2017;376:2545)

Mod: I&D + TMP-SMX or doxycycline

Severe: I&D + IV vanc, daptomycin or linezolid (± clinda for toxic shock syndrome)

• 在嚴重的感染，等待培養出來前，我會先經驗性給後線可以Cover MRSA抗生素，
• 如Vancomycin, Dpatomycin, Linezolid, Ceftaroline, 當然Baktar也是可以考慮一下
• 如果結果是MSSA，就可以考慮降

Mild: abscess <2 cm, no systemic signs of infection, immunocompetent, no indwelling hardware; moderate: systemic signs; severe: SIRS or immunosuppressed

儘管目前的指南建議對小於 2 cm 的單純化膿性膿腫單獨切開引流，但最近的數據表明，即使在較小的膿腫中，輔助抗生素治療也可能導致更高的治愈率。對於較大的膿腫，需要進行輔助抗菌治療。 用🦎 的話說：就是小於2cm雖然guideline說是引流就好，但有抗生素好得快

• Limb elevation; erythema may worsen after starting abx b/c bacterial killing → inflam.
  • 肢體抬高；開始 abx b/c 細菌殺滅 → 發炎後，紅斑可能會惡化。
• In obese Pts, adequate drug dosing important to avoid treatment failure (J Infect 2012;2:128)
• Duration: 5 to up to 14 d based on severity and response to treatment. Take pictures & draw margins to track progress.