1. Skin and Soft-Tissue Infections Superficial lesions vs Deadly disease Outpatient Management and Indications for Hospitalization
Nayef El-Daher, MD, PhD
Richard Magnussen, MD
J Crit Illness, 1998; 13(3):
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2. Skin and soft-tissue Infections
Localized infections
cellulitis
erysipelas
Potentially lethal infections
necrotizing fascitis
myonecrosis
pyomyositis
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3. Cellulitis and Erysipelas pathogenesis
group A streptococci typically follows an innocuous or unrecognized injury; inflammation is diffuse, spreading along tissue planes
staphylococcus aureus usually associated with wound or penetrating trauma; localized abscess become surrounded by cellulitis
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4. Cellulitis and Erysipelas pathogenesis
caused most often by group A streptococci
rarely cased by ß-hemolytic streptococci of the B, C, or G serologic group
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5. Cellulitis and Erysipelas diagnosis
General features
varying degrees of skin or soft-tissue erythema, warmth, edema, and pain
associated fever and leukocytosis
history of trauma, abrasion, or skin ulceration (not reported by every patient)
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6. Cellulitis and Erysipelas diagnosis
physical exam
cellulitis has an ill-defined border that merge smoothly with adjacent skin; usually pinkish to redish
erysipelas has an elevated and sharply demarcated border with a fiery-red appearance
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7. Cellulitis and Erysipelas diagnosis
laboratory exam
needle aspiration of the leading edge of the cellulitis should be obtained (1)
elevated antistrptolysin O titer supports diagnosis of streptococcal infection
blood cultures for patients with symptoms of toxicity or temp > 1020F
1. Arch Intern Med 1990; 150:
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8. Cellulitis and Erysipelas management
Local care
immobilization
elevation to reduce swelling
2 weeks of antibiotic therapy
penicillin and dicloxacillin for most pts
many new, potent and expensive antibiotics offer no advantage
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9. Outpatient Therapy Infection Most patients Pencillin allergic patients
Cellulitis
mild-mod Dicloxacillin Cephalexin 500mg po q6h
(500 mg po q6h) Clindamycin 450mg po q6h
severe Nafcillin 1-2g iv q4h Cefazolin 1g iv q8h
Vancomycin 1g iv q12h
Erysipelas
mild-mod Penicillin V Cephalexin 500mg po q6h
(500 mg po q6h) Erythromycin 500mg po q6h
Clindamycin 450mg po q6h
severe Pen G 1-2 million U q6h Cefazolin 1g iv q8h
Clindamycin 900mg iv q8h
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10. Admission Criteria for Cellulitis
Animal bite on patient’s face or hand
Area of skin involvement >50% of limb or torso, or >10% of body surface
Coexisting morbidity (diabetes, heart failure, renal failure, generalized edema)
Edge of cellulitis advancing at rate exceeding 5cm, or 2 in, per hour
History of saphenous venectomy, pelvic surgery, pelvic irradiation, or neoplastic pelvic lymph nodes (with lower extremity cellulitis)
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11. Admission Criteria for Cellulitis
Immunosuppression
Intolerance of oral or IM antibiotic therapy
Lack of response after 72 hours of oral therapy
Noncompliance with medication and follow-up visits
Purpuric or petechial rash, numbness at skin surface, or impaired tendon or nerve function
shock or disseminated intravascular coagulation
Signs and symptoms suggestive of bacteremia
Total WBC < 1000 / uL
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12. Necrotizing Fasciitis pathogenesis
a polymicrobial infection, commonly caused by a mixture of anaerobic and aerobic bacteria
clostridium species, enterobacteriaceae ( E. coli, Enterobacter, Klebsiella, and Proteus species), and “flesh-eating” streptococci
usually starts at the site of nonpenetrating trauma (a bruise)
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13. Necrotizing Fasciitis diagnostic clues
Underlying diabetes mellitus, peripheral vascular disease, alcoholism, intravenous drug use or immunosupression
Most often involve the lower extremities
Infected area is swollen, erythematous, painful, warm, and very tender
Rapidly advancing border (5 cm, or 2 in, per hour) of discoloration (red to blue-gray)
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14. Necrotizing Fasciitis diagnostic clues
Bulllae formation and cutaneous gangren
Frank pus in discolored area (revealed by needle aspiration or surgical exploration)
Numerous bacteria evident on the Gram stain
Tendon or nerve impairment (superficial nerve destruction and small vessel thrombosis)
Systemic toxicity and/or hypotension
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15. Necrotizing Fasciitis management
Immediate surgical debridement is critical and life saving
empiric antibiotics to cover anaerobes, gram negative bacilli, streptococci, and Staph aureus
pen+metronidazole+clindamycin+ceftriaxone
vancomycin+chloramphenicol
monotherapy with imipenem
antibiotics for a minimum of 3 wks
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16. Myonecrosis (Gas Gangrene)
a pure Clostridium perfringens infection
gas in a gangrenous muscle group
incubation period of hours to days
local edema and pain accompanied by fever and tachycardia
discharge is serosanguinous, dirty, and foul
pen G (3-4 million U q4h) or chloramphenicol
surgical removal of infected muscle
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17. Pyomyositis (tropical myositis)
50% with co-morbidity (diabetes, alcoholic liver disease, concurrent corticosteroid therapy, immunosuppression)
endemic in the tropics
area is indurated with a “woody” consistency; erythema and tenderness is minimal initially
fever and marked muscle tenderness may develop in 1-3 weeks
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18. Pyomyositis (tropical myositis)
Rhabdomyolysis - along with myoglobinuria and acute renal failure - may develop
Staph aureus is the most common organism
MRI or CT may show muscle enlargement
surgical drainage is essential
empiric antibiotics directed against Staph
nafcillin 2 g iv q4h
vancomycin 1 g iv q12h or cefazolin 1g iv q8h
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