Skin and Soft Tissue Flashcards
(102 cards)
1
Q
What is the first line of defense against microbial invasion?
A
Intact Skin
2
Q
What do Rubor, Calor, Tumor, and Dolor mean respectively?
A
- Redness (erythema)
- Warmth
- Edema
- Tenderness (pain)
3
Q
What did he say causes Crepitus?
A
-
4
Q
What diseases would mimic a SSTI and would require a differential diagnosis?
A
- Gout
- Thrombophlebitis
- Deep vein thrombosis
- Contact Dermatitis
- Drug Eruption
- Foreign body reaction
5
Q
What is folliculitis?
A
Minor infection, associated with friction and sweat gland activity
6
Q
What types of bacteria can cause folliculitis?
A
- Staph Aureus
2. Pseudomonas Aeruginosa
7
Q
What bacteria causes Hot tub folliculitis?
A
Pseudomonas Aeruginosa
8
Q
How do you treat folliculitis?
A
Soap and water; Topical antibiotics
9
Q
What bacteria cause Acne?
A
Propionibacterium acnes
10
Q
How does Propionbacterium cause acne?
A
Multiplies behind or within sebum trapped in follicles or glands
11
Q
Define Acne
A
Inflammation of hair follicles associated sebaceous glands
12
Q
What can contribute to Acne?
A
Hormonal influences, organic acids produced by P. acnes
13
Q
What is the most common cause of soft tissue abscess?
A
Staph aureus (this includes MRSA)
14
Q
What causes a soft tissue abscess?
A
Any breach in the skin
15
Q
What areas are often polymicrobial?
A
- Oral
- rectal
- Vulvo-vaginal
- IV drug users also
16
Q
What is a Furuncle?
A
-Abscess in the area of a hair follicle
17
Q
What is a furuncle often referred to as?
A
Boil
18
Q
T/F Furuncles are often recurrent
A
TRUE
19
Q
What is a carbuncle?
A
- Multilocated abscess
- Spread of infection to subcutaneous tissue
20
Q
What causes a Carbuncle?
A
Staph Aureus
21
Q
How do you treat a carbuncle?
A
Incision and drainage
22
Q
What bacteria cause Necrotizing Fasciitis?
A
- Group A strep
- Staph Aureus
- Anaerobic: Colstricium perfringens (spores)
23
Q
What is the virulence factor of Necrotizing Fasciitis?
A
Enzyme-producing bacteria that digest fascial barriers and cause tissue necrosis
24
Q
At what rate can necrotizing fasciitis spread
A
rapidly
25
What is Fournier's gangrene?
Polymicrobial infection of the genitals and perineum
26
Describe pain as a symptom of necrotizing fasciitis
Pain is usually out of proportion to exam findings
27
What are some common symptoms of necrotizing fasciitis?
- Edema
- Erythema
- Pain
- Crepitus * (rare)
28
What is the most common pathogen in surgical wound infections?
Staph Aureus
29
Where does the Staph Aureus come from to infect surgical wounds?
1. Patient's own skin or normal flora
2. Transmission by fomites, hands, air
3. Environmental
30
What is a fomite?
Inanimate objects that can transmit pathogenic organisms
31
What is the main where to prevent surgical wounds?
Perioperative antibiotics
32
What are the 3 genera that cause fungal infections?
1. Trichophyton
2. Microsporum
3. Epidermophyton
33
What is the most common yeast infection?
Candida Albicans
34
How do you treat Candida albicans infections?
Topical antifungals; systemic antifungals if severe
35
What are the most common fungal infections that we see?
Dermathophyte fungi-Tinea Cruris, Corporis,
36
What type of infections do dermatophyte fungi cause?
Superficial hair skin and nail infections
1. Ringworm
2. Nail infections: onchomycosis
3. Keratinized layers of skin or nails
37
What areas of the body are more prone to yeast infections?
Warm, most areas of the body: Mouth, vagina, armpit, fat folds, butt
38
What are three examples of yeast infections caused by candida?
1. Diaper rash
2. Intertrigo
3. Thrush
39
Where would you find an impetigo infection?
Epidermis
40
What does impetigo look like?
Honey crust
41
What are two things that cause impetigo?
1. Group A. Strep
| 2. Staph Aureus
42
T/F Impetigo is ugly but not contagious
FALSE, it is highly contagious
43
How do you treat Impetigo?
Penicillin, topical Antibiotic
44
What Causes Erysipelas?
Group A strep
45
Where would an Erysipelas infection be in the skin?
Deep layers of dermis
46
How do you treat Erysipelas?
Penicillin
47
T/F Erysipelas spreads rapidly
TRUE
48
What are some systemic signs that might accompany Erysipelas
Maybe a fever and headache, etc
49
What causes Cellulitis?
1. Group A strep 2. Staph Aureus
| 3. Gram Negatives
50
Where in the skin does a cellulitis infection occur?
Subcutaneous tissue
51
In what situations would Gram negatives cause Cellulitis?
1. Immunocompromised
2. Nosocomial
3. Wounds
4. Diabetes Mellitus
52
How do you treat cellulitis?
Systemic antibiotics
53
Is culture useful with cellulitis?
Not really
54
What factors increase risk of wound infections?
1. High number or organisms
2. Higher Virulence of Organisms
3. Poor circulation near wound
4. Poor General health
5. Poor nutrition status
6. Diabetes
7. Immune comporomise
55
What is the all time champion of microbial pathogens?
Staphylococcus Aureus
56
Puss causes _____, ___, locally destructive __ lesions
1. Acute
2. Aggressive
3. Purulent
57
Where does staph colonize?
Anterior nares
58
What percent of the population is carrying staph at any given time?
10-30% although that percentage is higher in healthcare workers and patients
59
T/F once in skin, staph easily accesses deeper tissue through skin appendages or trauma
TRUE
60
What can alpha toxins from staph cause?
Staph scalded skin syndrome
61
What is Exfoliatin
Bullous Impetigo
62
What does TSST-1 cause?
Staph Toxic Shock syndrome
63
What toxin will cause Staphylococcal food poisoning?
Enterotoxin
64
What does MSSA stand for?
Methicillin-Sensitive Staphylococcus Aureus
65
How does MRSA become resistant to Beta lactams?
- Acquires mecA gene
- Makes new PBP with reduced affinity for Beta-Lactams
- Resistant to all Beta-lactams
66
What are the drugs of choice for MSSA?
1. Anti-Staphylococcal PCN
- Nafcillin
- Oxacillin
2. Cephalosporins
67
What are risk factors for MRSA
1. Close skin-skin contact
2. Crowded Living conditions
3. Poor hygiene
4. IV drug use
68
How do you treat MRSA?
1. Trimethoprim-Sulfa
2. Doxycycline
3. Vancomycin
4. Linezolid
5. Daptomycin
69
What are some Post-Strep sequelaes?
1. Rheumatic fever
- can follow Pharyngitis
2. Post-strep glomerulonephritis
- can follow Pharyngitis or soft tissue infection
70
Group A strep has over ____ serotypes on antigenic differences in _____
1. 100
| 2. M protein
71
In what way are Streptolysins O and S cytotoxic?
They lyse leukocytes, tissue cells, and platelets
72
Name 3 enzymes produced by Group A strep
1. Streptokinase
2. hyaluronidase
3. DNase
73
What does Streptokinsase doe?
It is a protease
74
What does Hyaluronidase do?
Degrades Carbohydrates
75
What does DNase do?
Degrades DNA
76
Describe Clostridium perfringens
Anaerobic, spore-forming, gram positive rod with square ends
77
Where would you find Clostridium Pergringens?
Soil and human colon
78
What kind of infections can C. Perfringens cause?
Soft tissue infections:
1. Wound infection
2. Gas Gangrene: Traumatic wounds contaminated with spores from dirt or host's own intestinal flora
3. These infections can be rapidly fatal
79
T/F C. perfringens produces Hydrogen and CO2 gas in tissue and has multiple exotoxins
TRUE
80
What causes Pasteurella multocida and how do you get it?
Caused by gram negative rods and you can get it from animal bites
81
Describe Pseudomonas aeruginosa
Gram negative rod
82
Does P. Aeruginosa ferment things?
It is a prototypical non-fermenter
83
Where can you find P. Aeruginosa?
Environmental Pathogen:
- Water
- Hospital rooms
84
What can P aeruginosa cause?
- Numerous skin infections
- Examples:
- Hot tub folliculitis
- Secondary infection after burns
85
Describe Vibrio vulnificus
Gram negative rod
86
Where would you find vibrio vulnificus?
In salt water environments: colonize shellfish
87
What is vibrio vulnificus associated with?
Iron overload and cirrhosis
88
What does the progression of vibrio vulnificus look like?
Fever -> Sepsis --> Hemorrhagic Bullae
89
What do you call a Mycetoma infection?
Madura foot
90
What bacteria can cause Madura foot?
- Actinomyces
| - Nocardia
91
T/F Madura foot can also be caused by fungus
TRUE
Lots of molds
92
What causes Sporotrichosis?
Sporothrix schenckii: rose gardener's thumb
93
A microbiological diagnosis is often ____
Clinical
94
In a microbiological diagnosis, surface cultures are often ____, and rarely have _____
- Positive
| - the pathogen causing the infection
95
Biopsies of microbiologic infections are rarely ____
Positive
96
Inflammation in infected areas is often due more to _____ rather than _____
- immune response
| - "lots" of organisms
97
What is pus great for?
Diagnosis
98
If the infection is severe what can you use to help diagnose?
Blood cultures
99
If you see an abscess on the skin, what organism should you suspect?
Staph aureus
100
If you see an abscess in the mouth, rectum, or vagina what should be be thinking?
Polymicrobial infection
101
If you diagnose Cellulitis or Erysipelas what organisms should you be thinking of?
Strep pyogenes (Group A strep)
102
What are some host and exposure considerations to detect other possible pathogens in an infection?
- IVDU: pseudomonas
| - Cat or dot bites: Pasteurella
