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Source: Fish
DN, Pendland SL, Danziger LH. Skin and Soft-Tissue Infections. In:
DiPiro, JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey LM. Pharmacotherapy:
A Pathophysiologic Approach. 8th edition. http://accesspharmacy.com/content.aspx?aid=8002378.
Accessed July 21, 2012.
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- Acute, spreading, infectious process that initially affects
epidermis and dermis; may subsequently spread within superficial
fascia.
- Process characterized by inflammation but
with little or no necrosis or suppuration of soft tissue.
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- Most often caused by S. pyogenes or S. aureus.
- Increased incidence of methicillin-resistant S. aureus (MRSA) of major concern.
- Mixed aerobic and anaerobic pathogens seen:
- In
diabetics
- Following traumatic injuries
- At sites of abdomen or perineum surgical incisions
- With compromised host defenses (e.g., vascular insufficiency)
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- Spreading inflammatory infection following wound from
minor trauma, abrasion, ulcer, or surgery.
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- Considered a serious infection due to propensity to spread
through lymphatic tissue and to bloodstream.
- 10% of all infection-related hospital admissions
between 1998 and 2006
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- Injection drug use
- History of antecedent wound from minor trauma, abrasion, ulcer,
or surgery.
- Poor nutrition
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- Characterized by erythema and edema of the skin.
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- Fever
- Chills
- Malaise
- Erythema and edema of skin; affected areas warm to touch
- Lesions nonelevated, with poorly defined margins
- Inflammation present, with little or no necrosis or suppuration
of soft tissue
- Tender lymphadenopathy
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Means of Confirmation
and Diagnosis
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- Diagnosis usually based on appearance of lesion.
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- Complete blood count (CBC): leukocytosis common.
- Cultures of affected area may be difficult.
- Gram stain of fluid obtained by injection and aspiration of
saline.
- Blood cultures: bacteremia present in as many as 30% of
cellulitis cases.
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- Injection and aspiration of 0.5 mL saline into advancing
edge of lesion may aid microbiologic diagnosis, but is often negative.
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Differential
Diagnosis
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- Rapid eradication of infection
- Prevention of complications
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- Selection of antimicrobial therapy directed toward type
of bacteria documented to be present or suspected.
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- Elevation and immobilization of involved area to decrease
local swelling
- Cool, sterile saline dressings may decrease pain.
- Follow with moist heat to aid in localization of infection.
- Surgical incision and drainage rarely indicated in uncomplicated
disease.
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- Administration of semisynthetic penicillin (nafcillin
or oxacillin) or first-generation cephalosporin (cefazolin) recommended
until definitive diagnosis, by skin or blood cultures, can be made
(Tables 1 and 2).
- Oral or parenteral clindamycin recommended for penicillin-allergic
patients.
- Usual duration of therapy: 5–10 days
- If
caused by gram-negative bacilli or mixture of microorganisms, treat
for 10–14 days.
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