Cellulitis

Question 1

Cellulitis

Answer 1

Cellulitis (which includes erysipelas) manifests as an area of skin erythema, edema and warmth which developed as a result of a bacterial entity via breech in the skin barrier.

Question 2

Cellulitis Pathogens

Answer 2

• β-hemolytic streptococci (groups A, B, C, G and F), most commonly Group A Streptococcus or Streptococcus pyogenes
• S. aureus (including MRSA) is less common
• G-negative aerobic bacilli are identified in a minority of cases.

Question 3

S/S of Cellulitis

Answer 3

-Begins as a small patch which expands over hours. This is nearly always unilateral.
-Initial symptoms
Swelling
Erythema
Pain
-Late symptoms
Chills
Fever
Malaise
If septicemia develops, hypotension followed by shock may develop

Question 4

Imaging for Cellulitis

Answer 4

-Warranted in patients with underlying immunosuppression, diabetes, venous insufficiency, lymphedema and persistent systemic infections.

• Ultrasonography: used to determine if a skin abscess is present.
• MRI: Used to distinguish cellulitis from osteomyelitis.
• X-ray: Cannot reliably distinguish between cellulitis and necrotizing fasciitis or gaseous gangrene.

Question 5

Osteomyelitis

Answer 5

• Can occur without evidence of local soft tissue infection, more common with ulcer size greater than 2 cm in depth allowing visibly exposed bone or ability to probe to bone.
• Erythrocyte sedimentation rate level of 70 or greater increases the clinical probability of osteomyelitis.
• Plain radiograph will reveal cortical erosion, periosteal reaction and mixed lucency.
• MRI will reveal cortical destruction, bone marrow edema and soft tissue inflammation.

Question 6

Stasis Dermatitis

Answer 6

A typically bilateral inflammatory dermatosis of the lower extremities that occurs in patients with chronic venous insufficiency

Question 7

Lymphedema

Answer 7

Abnormal accumulation of interstitial fluid resulting from injury or anatomic abnormality of the lymphatic system.

Question 8

General Guidelines

Answer 8

• purulent and nonpurulent infections should be managed with empiric antibiotic therapy.
• If antibiotics are warranted, symptom improvement generally occurs within 24-48 hours but skin improvement may take 72 hours.
• Duration: 5 days in most cases but can be increased to up to 14 days for slow responders

Question 9

Drainable abscess

Answer 9

• should undergo incision and debridement with antibiotic treatment if warranted.
• -Single abscess ≥ 2cm
• –Multiple abscesses
• -Extensive surrounding cellulitis
• -Immunosuppression
• –Systemic signs of infection
• -Presence of an indwelling medical device
• –High risk for adverse outcomes with endocarditis
• –High risk for transmission of S. Aureus to others.

Question 10

Non-Purulent Cellulitis Empiric Therapy for B-hemolytic strep and MSSA

Answer 10

--Oral: 
Dicloxacillin: 500 mg QID
Cefadroxil: 1 g daily
Cephalexin: 500 mg QID
Clindamycin (beta-lactam allergy): 300 mg QID

-Parenteral:
Cefazolin: 1-2 g  every 8 hours
Nafcillin: 1 g every 4 hours
Oxacillin: 2 g every 4 hours
Clindamycin (beta-lactam allergy): 600-900 mg every 8 hours

Question 11

Non-Purulent Cellulitis Empiric Therapy for B-hemolytic strep and MRSA

Answer 11

Oral
Bactrim: 1-2 DS tablets BID
Amoxicillin/doxycycline: 875 mg BID / 100 mg BID
Amoxicillin/minocycline: 875 mg BID / 200 mg once, then 100 mg BID
Clindamycin: 300 mg QID

Parenteral
Vancomycin: 15 to 20 mg/kg/dose every 8-12 hours
Daptomycin: 4 to 6 mg/kg every 24 hours

Question 12

Purulent Infection Tx: If none of the following present-Perioral or perirectal location of abscess.
Potential fistula between ulcer and abscess.
Prominent skin necrosis.

Answer 12

-Oral:
Bactrim: 1 to 2 DS tablets BID
Doxycycline: 100 mg BID 
Minocycline: 200 mg once, then 100 mg BID
Clindamycin: 300 mg QID

-Parenteral
Vancomycin: 15 to 20 mg/kg/dose very 8 to 12 hours
Daptomycin: 4 to 6 mg/kg every 24 hours

Question 13

Purulent Infection Tx: If any of the following present
Perioral or perirectal location of abscess
Potential fistula between ulcer and abscess
Prominent skin necrosis

Answer 13

Oral

• Bactrim with Augmentin: 1 to 2 DS Tabs BID / 875 mg BID
• Doxycycline with Augmentin: 100 mg BID / 875 mg BID
• Doxycycline with levofloxacin & Flagyl: 100 mg BID / 750 mg daily / 500 mg TID
• Clindamycin with Augmentin 300 mg QID / 875 mg BID
• Clindamycin with ciprofloxacin 200 mg QID / 500 mg BID

Question 14

Purulent Infection Tx: If any of the following present
Perioral or perirectal location of abscess
Potential fistula between ulcer and abscess
Prominent skin necrosis: Parenteral

Answer 14

-One of the following:
-Vancomycin: 15 to 30 mg/kg/dose every 8 to 12 hours
-Daptomycin: 4 to 6 mg/kg every 24 hours
Plus
-Unasyn: 3 g every 6 hours
-Zosyn: 3.375 or 4.5 g every 6 hours
-Ceftriaxone & Flagyl: 1 to 2 g every 24 hours / 500 mg TID
-Ciprofloxacin & Flagyl: 400 mg every 12 hours / “ ”
-Levofloxacin & Flagyl: 750 mg every 24 hours /