Cellulitis


_* yo M/F with PMH of *, presenting with
* days _constant/intermitent, progressively worsening/improving

  • CC: unilateral erythema, warmth, swelling, skin tenderness

  • PP: edema, warmth, tenderness, recent skin trauma/cut/insect bite, drainage, progressive redness

  • PN: fever, chills, rapid spread, severe pain out of proportion, deep muscle pain, crepitus, bullae, necrosis, ulcers, fluctuance, improves with elevation, denies (immobility, cancer, recent surgery)

  • pertinent SHx: tobacco, EtOH, drug use, IVDU

  • Etiology: most commonly streptococcal species and MSSA; consider MRSA in purulent cellulitis or high-risk patients

  • risk factors: DM, obesity, chronic edema/lymphedema, venous stasis, immunocompromised state, skin breakdown, prior cellulitis, tinea pedis, IVDU

  • initial DATA: CBC, BMP, ESR/CRP, blood cultures if systemic symptoms, wound culture if drainage, US if concern for DVT/abscess

  • pending DATA: BCx, wound cx, MRSA nares, imaging results

  • DDX: erysipelas, pyomyositis, necrotizing fasciitis, osteomyelitis, venous stasis

  • Hospital course:

Plan:

  • mild: PO Cephalexin/Keflex 500 mg QID (( Localized infection and No systemic signs ))

  • mild + purulence: (Bactrim) 1–2 DS BID (cover MRSA)

  • Mod/Severe: IV Cefazolin/Ancef 2g q8h (SIRS criteria ≤2)

  • Mod/Severe + purulence : IV Cefazolin 2g q8h + Vanc

  • Duration 5 days if improvement, if not Extend to 10–14 days

  • if abscess present → Incision & Drainage is essential + Vanco sould be on regiment

  • F/U cultures

  • trend CBC,RFP daily

  • would care consult at place

  • PT/OT to eval

  • if become septic broaden tx: vancomycin plus meropenum

  • CT if c/f nec fasc, pyomyositis, or osteomyelitis

  • if necrotizing fasciitis urgent surgery consultation (rapid spread of infection, crepitus, air in tissues on imaging, or pain out of proportion to exam) will need CT w/contrast

Note

  • Blood cultures  ONLY if systemic signs of infection or immunodeficiency 

  • Mild, not meeting SIRS, Immunocompetent, no systemic signs , low suspicion for MRSA -> Cephalexin or Dicloxacillin both 500 mg QID (PO), if Purulent / MRSA suspected -> TMP-SMX (Bactrim) 1–2 DS BID or Doxycycline 100 mg BID

  • Moderate/severe ≥2 SIRS (systemic signs of infection)-> Cefazolin 2g q8h, and if purulent/MRSA suspected add Vanco, PO step down: cephalexin 500 mg q6h or 1000mg q8h and for MRSA Linezolid 600 mg PO BID

  • Severe cellulitis / purulent (penetrating trauma, MRSA risk factors, injection drug use, purulent drainage, or SIRS): add Vancomycin and then step down: TMP/SMX 1-2 DS tabs BID or Doxycycline 100 mg BID or Linezolid 600 mg BID

  • Duration is 5 days if clinical improvement occurs; extend if not improving to Extend to 10–14 days

  • If abscess present → Incision & Drainage (I&D) is essential + Vanco sould be on regiment

  • if become septic broaden tx: vancomycin plus meropenum

  • CT/MRI w/contrast: if necrotizing fasciitis, pyomyositis or osteomyelitis suspected

  • if necrotizing fasciitis urgent surgery consultation (rapid spread of infection, crepitus, air in tissues on imaging, or pain out of proportion to exam) will need CT w/contrast

  • mild has Localized skin infection and No systemic signs of infection , tx po

  • Moderate WITH systemic signs of infection - Fever >38°C, Tachycardia >90, Tachypnea >20, Leukocytosis. tx iv

  • for mild other abx options are Dicloxacillin 500 mg QID or Amoxicillin-clavulanate 875 mg BID for 5 days

  • Pathogens: Streptococcus species: Group A (most common), B, C, G, Staphylococcus aureus (including MSSA and MRSA)

  • Non-purulent Think Streptococcus

  • Purulence (abscess or boil)? Think Staphylococcus 

  • Typically improvement is not seen until >48 hours of antibiotics, usually longer

  • Bilateral lower extremity cellulitis is RARE usually unilateral 

  • Unlikely cellulitis as erythema fades after pt raises the leg for 1–2 minutes.

  • Clues favoring DVT

    • Diffuse unilateral swelling > redness

    • Calf circumference asymmetry

    • Deep calf pain with walking/dorsiflexion

    • Minimal skin warmth

    • Strong VTE risk factors (immobility, cancer, recent surgery)