Skin and Soft Tissue Kristine Krafts, M.D. June 6, 2008 Infections.
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Transcript of Skin and Soft Tissue Kristine Krafts, M.D. June 6, 2008 Infections.
• Bad infections• cellulitis• necrotizing fasciitis• necrotizing myositis
• Not-so-bad infections• impetigo• folliculitis• furuncles and carbuncles• abscess• superficial fungal infections• deeper fungal infections
Skin and Soft Tissue Infections
BACTERIA
Gram-positive
Cocci• Staphylococcus• Streptococcus
Rods• Bacillus• Clostridium• Actinomyces• Corynebacterium• Listeria
Gram-negative
Cocci• Neisseria
Rods• A sh*tload
Weird• mycobacterium• spirochetes• chlamydia• rickettsiae• mycoplasma
• Infection of skin with some extension into subcutaneous tissues
• Most common location: extremities
• Strep pyogenes, Staph aureus
• Rarely, Clostridium perfringens (bad)
Cellulitis
Things you must know
• Swelling, erythema, warmth
• Lymphangitis, tender lymphadenopathy
• Maybe ringworm or psoriasis
• Maybe systemic symptoms
Cellulitis
Symptoms
• Erysipelas
• Clostridial cellulitis
• Nonclostridial anaerobic cellulitis
Cellulitis
Special forms of cellulitis
• Erysipelas• painful, bright red, swollen skin• Streptococcus pyogenes• kids, elderly• legs, face
Cellulitis
Special forms of cellulitis
• Erysipelas
• Clostridial cellulitis• Local trauma, surgery• Gas in skin• Need surgical exploration
Cellulitis
Special forms of cellulitis
• Erysipelas
• Clostridial cellulitis
• Nonclostridial anaerobic cellulitis• Diabetes • Gas in skin• Foul odor• Need surgical exploration
Cellulitis
Special forms of cellulitis
• Infection of fascia and fat; may spare skin
• Follows trauma (often mild)
• Strep pyogenes
• Often fatal
Necrotizing Fasciitis
Things you must know
• Diabetes-associated• mixed flora• feet → leg fascia
Necrotizing Fasciitis
Special forms of necrotizing fasciitis
• Diabetes-associated
• Head and neck fasciitis• after surgery or dental work• Ludwig’s angina
Necrotizing Fasciitis
Special forms of necrotizing fasciitis
• Diabetes-associated
• Head and neck fasciitis
• Fournier’s gangrene• Extension into GI/urethral mucosa• Aggressive• Severe pain
Necrotizing Fasciitis
Special forms of necrotizing fasciitis
• Unexplained, excruciating, increasing pain
• Erythema
• In 1-2 days: erythema darkens; bullae appear
• Fever, myalgias, anorexia, hypotension
Necrotizing Fasciitis
Symptoms
• Treat aggressively with repeated surgical debridement, antibiotics, fluid replacement
• Can spread to multiple organ systems
• High mortality
Necrotizing Fasciitis
Clinical course
• Bad infections• cellulitis• necrotizing fasciitis• necrotizing myositis
Skin and Soft Tissue Infections
• Uncommon infection of muscle
• Develops rapidly
• Clostridium
• Often fatal
Necrotizing Myositis
Things you must know
• Clostridium perfringens• Deep, penetrating injury• Bowel surgery• Post-abortion with retained placenta
• Clostridium septicum• Non-traumatic• May enter through GI
Necrotizing Myositis
Etiology
• Organisms injected into tissue
• Tissue damage → anaerobic environment
• Necrosis starts within 36 hours
• Clostridial toxins cause damage• theta toxin: vessel injury• alpha toxin: heart injury, cell lysis
Necrotizing Myositis
Pathophysiology
• Sudden, severe pain
• Bronze, then purple-red skin
• Bullae and crepitus (gas)
• Systemic signs
Necrotizing Myositis
Symptoms
• Aggressive surgical debridement
• IV antibiotics
• Hyperbaric oxygen
• Fatal without early debridement
Necrotizing Myositis
Clinical course
• Bad infections• cellulitis• necrotizing fasciitis• necrotizing myositis
• Not-so-bad infections• impetigo
Skin and Soft Tissue Infections
• Superficial vesicopustular skin infection
• Children
• Face, extremities
• S. pyogenes, S. aureus
Impetigo
Things you must know
• Bad infections• cellulitis• necrotizing fasciitis• necrotizing myositis
• Not-so-bad infections• impetigo• folliculitis
Skin and Soft Tissue Infections
• Infection localized to hair follicles
• Multiple small pustules
• S. aureus, Pseudomonas
• Can lead to furunculosis
Folliculitis
Things you must know
• Bad infections• cellulitis• necrotizing fasciitis• necrotizing myositis
• Not-so-bad infections• impetigo• folliculitis• furuncles and carbuncles
Skin and Soft Tissue Infections
• Furuncle: infectious nodule around hair follicle
• Carbuncle: larger, subcutaneous abscess
• S. aureus
• Can be dangerous
Furuncles and Carbuncles
Things you must know
• Bad infections• cellulitis• necrotizing fasciitis• necrotizing myositis
• Not-so-bad infections• impetigo• folliculitis• furuncles and carbuncles• abscess
Skin and Soft Tissue Infections
• Localized infection of dermis, subcutaneum
• Arises from trauma, IV drug abuse
• S. aureus
• Bacteremia and distant infection can occur
Abscess
Things you must know
• Bad infections• cellulitis• necrotizing fasciitis• necrotizing myositis
• Not-so-bad infections• impetigo• folliculitis• furuncles and carbuncles• abscess• superficial fungal infections
Skin and Soft Tissue Infections
• Dermatophytes = molds that invade skin, other keratinized tissues
• Sources: humans, animals, soil
• Three genera• microsporum• trichophyton• epidermophyton
Dermatophytoses
• Most classified by location• Hair: tinea capitis, barbae• Skin: pedis, cruris, corporis• Nails: unguium
• Some other unique types• Tinea nigra• Piedra
Dermatophytoses
• Pink to yellow-brown macules on trunk/arms
• Hypo-/hyperpigmentation, scaling
• Malassezia furfur
• “Spaghetti and meatballs”
Tinea (Pityriasis) Versicolor
Things you must know
• Bad infections• cellulitis• necrotizing fasciitis• necrotizing myositis
• Not-so-bad infections• impetigo• folliculitis• furuncles and carbuncles• abscess• superficial fungal infections• deeper fungal infections
Skin and Soft Tissue Infections
• “Rose gardener’s disease”
• First: painless papule (hand)
• Then: open sore, lymphatic spread (nodules)
• Sporothrix shenckii
Sporotrichosis
Things you must know
• Tropical disease
• Swelling, nodules, pus with “grains”
• “Madura foot”
• Fungi (many) or Nocardia
Mycetoma
Things you must know