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

Bad infections cellulitis Skin and Soft Tissue Infections

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

Venous/lymphatic compromise Diabetes Alcoholism Cellulitis Predisposing factors

Swelling, erythema, warmth Lymphangitis, tender lymphadenopathy Maybe ringworm or psoriasis Maybe systemic symptoms Cellulitis Symptoms

Cellulitis

Strep pyogenes Staph aureus Haemophilus influenzae Clostridium perfringens Cellulitis Cause

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

Bad infections cellulitis necrotizing fasciitis Skin and Soft Tissue Infections

Infection of fascia and fat; may spare skin Follows trauma (often mild) Strep pyogenes Often fatal Necrotizing Fasciitis Things you must know

Necrotizing fasciitis

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

Ludwig’s angina

Diabetes-associated Head and neck fasciitis Fournier’s gangrene Extension into GI/urethral mucosa Aggressive Severe pain Necrotizing Fasciitis Special forms of necrotizing fasciitis

Fournier’s gangrene

Fournier’s gangrene after debridement

Unexplained, excruciating, increasing pain Erythema In 1-2 days: erythema darkens; bullae appear Fever, myalgias, anorexia, hypotension Necrotizing Fasciitis Symptoms

Early necrotizing fasciitis

Necrotizing fasciitis

Necrotizing fasciitis 9 days later

Necrotizing fasciitis 16 days later

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

Necrotizing myositis

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

Impetigo

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

Folliculitis

Hot tub folliculitis

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

“The bourgeoisie shall remember my boils!”

Furuncle

Carbuncles

Carbuncle

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

Staphylococcal abscess

Splinter hemorrhages in bacterial endocarditis

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

Slow-growing “Ringworm” Sharp margins Dermatophytes Dermatophytoses Things you must know

Dermatophytes = molds that invade skin, other keratinized tissues Sources: humans, animals, soil Three genera microsporum trichophyton epidermophyton Dermatophytoses

Microsporum

Microsporum and trichophyton

Calcofluor white stain (Candida)

Most classified by location Hair: tinea capitis, barbae Skin: pedis, cruris, corporis Nails: unguium Some other unique types Tinea nigra Piedra Dermatophytoses

Tinea corporis

Tinea cruris

Tinea pedis

Tinea nigra

Black piedra

White piedra

Pink to yellow-brown macules on trunk/arms Hypo-/hyperpigmentation, scaling Malassezia furfur “Spaghetti and meatballs” Tinea (Pityriasis) Versicolor Things you must know

Tinea (pityriasis) versicolor

Malassezia furfur

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

Sporotrichosis

Tropical disease Swelling, nodules, pus with “grains” “Madura foot” Fungi (many) or Nocardia Mycetoma Things you must know

Mycetoma

Mycetoma granules

Granule histology: tons of hyphae

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