Cellulitis

Background

• Acute non-purulent spreading infection of the subcutanous tissue, causing overlying skin inflammation
• Most often caused by strep, staph, MRSA
• H.flu is most common cause in the orbit.

Cellulitis of the leg

Clinical Features

• Rash
  • Local erythema, warmth, swelling
  • Tender indistinct margins
• Can be accompanied by fever, chills, malaise, headache, nausea/vomiting

Differential Diagnosis

Skin and Soft Tissue Infection

• Cellulitis
  • Hand cellulitis
  • Facial cellulitis
  • Orbital cellulitis
• Erysipelas
• Lymphangitis
• Folliculitis
• Hidradenitis suppurativa
• Skin abscess
  • Anorectal abscess
  • Bartholin gland abscess
  • Pilonidal abscess
  • Scrotal abscess
• Necrotizing soft tissue infections
  • Necrotizing fasciitis
  • Necrotizing myositis
  • Necrotizing cellulitis
  • Fournier's gangrene
• Mycobacterium marinum

Look-A-Likes

• Sporotrichosis
• Osteomyelitis
• Deep venous thrombosis
• Pyomyositis
• Purple glove syndrome
• Tuberculosis (tuberculous inflammation of the skin)

Hand and finger infections

• Bed bugs
• Closed fist infection (Fight Bite)
• Hand cellulitis
• Hand deep space infection
• Hand-foot-and-mouth disease
• Herpetic whitlow
• Felon
• Flexor tenosynovitis
• Paronychia
• Scabies
• Sporotrichosis

Look-Alikes

• Digital mixoid cyst

Diagnosis

Work-up

• Ultrasound can be helpful

Evaluation

• Generally clinical diagnosis, may be assisted by ultrasound (above)

Management

Antibiotics

Tailor antibiotics by regional antibiogram

Outpatient

• 5 day treatment duration
  • Cephalexin 500mg PO q6hrs OR
    • Add DS 1 tab PO BID if MRSA suspected
  • Clindamycin 450mg PO TID covers Strep and Staph

Pediatric Outpatient

• Cephalexin 25-50mg/kg/day PO divided q6-8h (max 500mg/dose) OR
  • Add 8-12mg/kg/day (TMP) PO divided BID if MRSA suspected
• Clindamycin 30-40mg/kg/day PO divided TID (max 1.8g/day)

Inpatient

• Vancomycin 20mg/kg IV q12hrs OR
• Clindamycin 600mg IV q8hrs OR
• Linezolid 600mg IV q12hrs OR
• Daptomycin 4mg/kg IV once daily

Pediatric Inpatient

• Vancomycin 15mg/kg IV q6hrs OR
• Clindamycin 10-13mg/kg IV q8hrs (max 900mg/dose) OR
• Linezolid <12yr: 10mg/kg IV q8hrs; >12yr: 600mg IV q12hrs

Saltwater related cellulitis

• Doxycycline 100mg PO/IV q12hrs daily + Cefepime 1g IV q12hrs x 10 days
• Ciprofloxacin 400mg IV q12hrs x 10 days

Freshwater related cellulitis

• Ciprofloxacin 500mg PO q12hrs x 10 days
• TMP/SMX 2 DS tablets PO q12hrs x 10 days
• Ceftriaxone 1g (50mg/kg) IV q24hrs

Predictors of Treatment Failure

• Fever (T>38°C) at triage (odds ratio [OR] 4.3)
• Chronic leg ulcers (OR 2.5
• Chronic edema or lymphedema (OR 2.5)
• Prior cellulitis in the same area (OR 2.1)
• Cellulitis at a wound site (OR 1.9)

See Also

• Hand cellulitis
• Erysipelas