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):151-160 3/98 medslides.com

Skin and soft-tissue Infections Localized infections cellulitis erysipelas Potentially lethal infections necrotizing fascitis myonecrosis pyomyositis 3/98 medslides.com

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 3/98 medslides.com

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 3/98 medslides.com

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) 3/98 medslides.com

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 3/98 medslides.com

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; 150:1907-1912 3/98 medslides.com

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 3/98 medslides.com

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 3/98 medslides.com

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) 3/98 medslides.com

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 3/98 medslides.com

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) 3/98 medslides.com

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) 3/98 medslides.com

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 3/98 medslides.com

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 3/98 medslides.com

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 3/98 medslides.com

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 3/98 medslides.com

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 3/98 medslides.com