Cellulitis
Background
- Acute spreading infection of the dermis and subcutanous tissue, causing overlying skin inflammation[1]
- Most often caused by streptococcus or staphylococcus (including MRSA)
- Risk factors[2]
- Previous cellulitis
- Wound or current leg ulcers
- Excoriating skin diseases
- Lymphedema
- Venous insufficiency
- Obesity
- Tinea pedis
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
- Erysipelas
- Lymphangitis
- Folliculitis
- Hidradenitis suppurativa
- Skin abscess
- Necrotizing soft tissue infections
- 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
Foot infection
Skin and Soft Tissue
- Cellulitis
- Erysipelas
- Abscess
- Puncture wound infection
- Paronychia
- Ingrown toenail (infected)
- Tinea pedis
- Infected wound / diabetic foot ulcer
Deep Tissue / Limb-Threatening
Bone and Joint
Look A-Likes
- Gout
- Pseudogout
- Charcot foot
- Peripheral artery disease
- Deep venous thrombosis
- Venous stasis dermatitis
- Sporotrichosis
- Contact dermatitis
- Calciphylaxis
- Lymphedema
- Erythema nodosum
- Stress fracture
- Reactive arthritis
Evaluation
- Generally clinical diagnosis, may be assisted by ultrasound (above)
- Ultrasound can aid in diagnosis - may see "cobblestoning" of subcutaneous fat due to accumulation of fluid in these tissues. Also helpful to evaluate for abscess.
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
- Cephalexin 500mg PO q6hrs OR
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
- Doxycycline 100mg PO/IV q12hrs daily + Cefepime 1g IV q12hrs x 10 days
- Ciprofloxacin 400mg IV q12hrs x 10 days
- 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[3]
- 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)
Disposition
- Admit for:
- Sepsis
- Significant hand, face, or genitalia infection
- Failure of outpatient treatment
- Significant comorbidity (e.g. immunocompromized, poorly controlled diabetes)
See Also
References
- ↑ Gunderson CG, Martinello RA. A systematic review of bacteremias in cellulitis and erysipelas. J Infect. 2012 Feb;64(2):148-55.
- ↑ Quirke M et al. Risk factors for nonpurulent leg cellulitis: a systematic review and meta-analysis. Br J Dermatol. 2017 Aug;177(2):382-394.
- ↑ Peterson D. et al. Predictors of failure of empiric outpatient antibiotic therapy in emergency department patients with uncomplicated cellulitis. Acad Emerg Med. 2014 May;21(5):526-31.