Concern for septic arthritis

  • Duration:

  • CC: erythema limited ROM and pain

  • O/C/P: ((s/g-c/i-w/i/u))

  • PP: Swelling/fullness around the joint, Malaise, fatigue

  • PN: DENIES Fever ± chills

  • mHx: gout / pseudogout, Recent infection, Immunosuppression: diabetes, steroids, chemo, HIV, rthritis / chronic joint disease, Skin wounds / cellulitis, Prosthetic joint

  • sHx: IVDU

  • initial DATA: CBC,CMP,ESR/CRP, Bcx x2 and lactate if febrile, X-ray

  • past Micro:

  • MEDS: Immunosuppressants,antibiotics

  • COURSE:

  • DDX: cellulitis, Diabetic foot infections_ (vascular insufficiency)

Plan

  • consult Ortho for arthrocentesis +/- wash out, fluid studies (WBC >50k)

  • ID consult for Abx management

  • Hold AC if pt taking

  • hold antibiotics before arthrocentesis unless unstable

  • IV Abx only if unstable ( septic shock ) CFPM+VANC

  • Trend CBC,BMP daily

  • follow up blood cultures

  • PT/OT when possible

  • trend fever curve

  • ** f/u Synovial Fluid WBC count, Neutrophils, stain and culture

Note

  • if not getting better might need MRI for complication

  • abx duration: usually 3-4 weeks

  • Synovial fluid WBC count >50,000/μL with >90% neutrophils is the classic finding, also Absence of crystals — Negative birefringent crystals (gout) or positively birefringent crystals (pseudogout)

Cellulitis


-- __Days
-- cc: Unilateral erythema
-- sudden/gradual onset, constant/intermittent course, worsening/improving /unchanged Progression
-- PP:
-- PN: fever, chills, w/o improves on elevation, rapid spread, Severe pain out of proportion, Deep muscle pain, no ulcers ,
-- PE: UL erythema (no pain out of proportion, crepitus, ulcers)
-- Data: CBC, BMP, LFTs, BCx if systemic, US (DVT)
-- Hx: previous Micro, cellulite, imunocopmpremised , IVDU, DM
-- Meds:
-- 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 and treat

  • 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

Plan/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.