Chapter 21 Microbial diseases of skin Flashcards

1
Q

what type of organism causes folliculitis?

A

bacteria; Staphylococcus aureus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what causes S. aureus to infect to cause folliculitis?

A

enters through a natural opening in the skin (hair follicle)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what 4 things can folliculitis appear on the skin as?

A

pimples
sty
furuncle
carbuncle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is a sty?

A

infected follicle of an eyelash

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

what is a furuncle?

A

(boil) abscess, localized region of pus surrounded by inflamed tissue
hard to treat with antibiotics (they do not penetrate well into abscesses)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what is a carbuncle?

A

very deep, hard round deep inflammation of tissue under skin
produces fever
more severe than furuncle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what type of organism causes impetigo?

A

bacteria; Staphylococcus aureus and also Streptococcus pyogenes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is the difference between non-bullous impetigo and bullous impetigo?

A

non-bullous: most common form/ occurs mostly in children/ mild form
bullous: “scalded skin syndrome” release 2 toxins = more severe

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what is a vesicle?

A

small fluid-filled lesions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

when does a vesicle become a bullae?

A

when it becomes larger than 1 cm in diameter

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what are macules?

A

flat lesions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are papules? pustules?

A

raised lesions
pustules contain pus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Which Gram + bacterium causes inflammatory acne?

A

Propionibacterium acnes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what are comedos?

A

whiteheads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what are comedones?

A

blackheads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what is a virulence factor?

A

anything that makes an organism more harmful to the host
- protection against sunlight
- surface proteins allowing for host attachment
- contains coagulase
- produce toxins
- secrete protein blocking chemotaxis of neutrophils
- resistant to opsonization
- super antigens

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the names of the toxins that cause scalded skin syndrome?

A

Exfoliative toxin A (localized)
Exfoliative toxin B (distant)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which two bacteria cause impetigo?

A

Staphylococcus aureus
Streptococcus pyogenes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How does TSST-1 affect the body?

A

Toxic shock syndrome;
due to toxins, it is life-threatening
- fever
- vomiting
- sunburn-like rash
- organ failure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Which organic acid produced by fermenting bacteria causes inflammation in the skin?

A

Propionibacterium acnes metabolizes sebum, eats glycerol and leaves fatty acids behind causing inflammatory acne

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Which type of acne is the most severe?

A

Nodular cystic acne

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the basis for subdividing Streptococcus into smaller divisions - specifically Greek letters?

A

Gets broken down into Greek letter groups based on whether it can:
- slightly lyse RBCs with hemolysin toxins (alpha-hemolytic)
- fully lyse RBCs with hemolysin (beta-hemolytic)
-don’t use hemolysin (gamma-hemolytic)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the basis for subdividing Streptococcus into smaller divisions - specifically serological group?

A

They are then further broken down into groups A-T based on what antigens they have in their cell walls

24
Q

Why are the Group A β Strep relevant?

A

Group A beta (aka: GAS) can fully lyse RBC so they are most commonly associated with human disease (most common human pathogens)

25
In what groups of people does Group B β Strep mainly cause disease?
- Newborn babies (can be passed during childbirth b/c mom has it apart of their microbiome) - Pregnant women - Elderly - Immunosuppressed people
26
What are the toxins that contribute to necrotizing fasciitis?
pyrogenic toxins - initiate a fever
27
Which bacterium is associated with water and can cause problems with swimmers or bathers?
*Pseudomonas aeruginosa* can cause Pseudomonas dermatitis (rash) b/c pores open up in warm water and bodies make the water alkaline allowing bacteria to flourish and then invade
28
How does measles spread?
through respiratory route (breathing, talking, etc)
29
What is the approximation incubation period of measles?
10-12 days
30
How does the chicken pox rash change over time?
First 3-4 days cause just vesicles Then vesicles fill with pus and rupture forming scabs
31
how does an adult with shingles give chicken pox to a child?
chicken pox and singles are caused by the same virus (Varicella-Zoster Virus) but chicken pox is due to the initial infection, and shingles is due to virus being reactivated within the body
32
Are the viruses present in the body continually between chicken pox and shingles?
Yes, they remain latent within the host’s cells peripheral nerves
33
Which form of herpes simplex most commonly manifests near the mouth?
Herpes simplex virus-1 (HSV-1)
34
How is oral herpes usually spread?
Orally or respiratory route
35
Which type of herpes simplex is much more common?
Herpes simplex virus-1 (HSV-1)
36
Where does herpes simplex type-2 show lesions?
around genitalia (genital herpes)
37
How do superficial mycoses obtain nutrients?
Use keratin as food source (hair, nails, and stratum corneum)
38
What are some genera of fungi that can infect the skin?
*Trichophyton Microsporum Epidermophyton*
39
Know the naming of ringworm infections based on their locations.
Tinea capitis – ringworm of scalp Tinea cruri – groin Tinea pedis – foot Tinea unguium – fingernails and toenails
40
What are the two skin parasites discussed in lecture?
*Sarcoptes scabiei* – scabies *Pediculus humanus* – lice
41
How are skin parasites usually transmitted to a new host?
direct contact
42
what are the two subspecies of body lice.
*Pediculus humanus capitis* : head louse *Pediculus humanus corporis* : body louse
43
Which subspecies of lice can transmit disease?
Pediculus humanus corporis: body louse (causes typhus)
44
what organism causes toxic shock syndrome?
gram + bacteria; *Staphylococcus aureus*
45
what type of bacteria cause erysipelas?
*Streptococcus pyogenes* Group A beta strep (GAS)
46
what is erysipelas?
reddish patches with raised margins (can be local and systemic)
47
what is Necrotizing fascilitis? what organism causes it?
*Streptococcus pyogenes* Group A beta strep (GAS) "flesh eating bacteria" causes extreme swelling and destruction of skin
48
what bacteria is associated with GBS? what does it stand for?
Group B beta strep *Streptococcus agalactiae*
49
what is the most common skin disease in humans? what organism causes it? what is its other name?
acne *Propionibacterium acnes* (Cutibacterium)
50
what are the three types of acne in order of increasing severity?
comedonal (mild) - white/blackheads inflammatory (moderate) nodular cystic acne (severe)
51
what is Rubeola? what organism causes it?
measles virus
52
what is Rubella? what organism causes it?
german measles virus
53
what are symptoms of rubeola?
cold rash on face/trunk/extremeties Pneumonia secondary bacterial infections encephalitis
54
what are symptoms of Rubella?
much milder than rubeola often goes undetected except when fetuses become infected = Deaf, heart defects, autism and death
55
what type of organism causes small pox? what is it?
virus rash that permanently disfigures
56
what is the difference between all three herpes viruses?
HSV: oral herpes HSV-2: genetal herpes HSV-3: chicken pox