Skin and Soft Tissue Infections Flashcards
1
Q
Skin anatomy (inside –> outside)
A
subcutaneous tissue
dermis
epidermis
2
Q
Skin (function/protective mechanisms)
A
- serves as a barrier
- contains keratin (water-resistant)
- high salt and acidic pH
- normal flora: S. epi, CoNS, Propionibacterium, Corynebacterium, yeasts
3
Q
Infections of the epidermis and dermis
A
- infection in/around hair follicles: folliculitis, furuncolosis, carbuncles
- infection of keratinized layer: dermatophyte fungi, Trichophyton, Epidermophyton, Microsporum
- infection of deeper layers: due to traumatic breaks in skin (erythrasma, hidradentis suppurativa, pilonidal cysts, sebaceous cysts)
4
Q
Folliculitis, furuncolosis, carbuncles (causes)
A
- S. aureus is most common
- Enterobacteriaceae
- Pseudomonas aeruginosa associated with hot tubs
5
Q
Trichophyton, Epidermophyton, Microsporum
A
- ringworm
- tinea pedis: athlete’s foot
- tinea versicolor: Malassezia furfur
6
Q
Erythrasma
A
- chronic infection of keratinized layer
- Corynebacterium, Mycobacterium marinum
7
Q
Hidradentis suppurativa
A
- obstructed apocrine gland (sweat gland)
- S. aureus, anaerobic strep, Bacteroides
8
Q
pilonidal cysts
A
B. fragilis
9
Q
Sebaceous cysts
A
Anaerobic cocci, bacteroides, propionibacterium, staphylococci, streptococci
10
Q
Subcutaneous tissue infections
A
- abscesses, ulcers, boils: S. aureus, polymicrobial
- Erisipelas: cellulitis and streptococcal necrotizing fasciitis
11
Q
Cellulitis
A
- usually in extremities, usually staph or strep
- anaerobic and aerobic mixed
- E. coli, Enterics, S. aureus, Strep, Anaerobes
12
Q
Necrotizing fasciitis
A
- Group A Strep, S. aureus, Bacteroides, Clostridium
- Gas gangrene: C. perfringens
13
Q
Infections of Muscle Fascia and Muscles
A
- Necrotizing fascitis
- Progressive bacterial synergistic gangrene (post-op infection, polymicrobial)
- Myositis
14
Q
Myositis
A
- extensive muscle involvement
- S. aureus, Clostridium, Group A and B strep
- Virbio vulnificus, Aeromonas, other wound-associated bacteria
15
Q
Wound Infections
A
- post-operative infections (normal flora or nosocomial organisms, S. aureus)
- human bite wounds (mouth flora, strep, S. aureus, Eikenella, Anaerobes)
- animal bite wounds (pasteurella, strep, staph, anaerobes)
- burns (Pseudomonas, S. aureus, Enterobacter, E. coli)
