Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Rob's Microbiology MCD > Micro 4: skin infection > Flashcards

Micro 4: skin infection Flashcards

1
Q

When are skin infections more commonly seen- GP or hospital

A

In GP it’s 25%

In hospital 5%

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

Where are high and low rates of skin infection seen

A
  • High rates of skin infection are seen in hot, humid and poor populations
  • Low rates are see in dry, temperate conditions, and rich populations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What type of bacterium is S. Aureus

A

Gram pos (cocci, from name)

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

What toxins does S. Aureus produce

A

Panton Valentine Leuocidin

Exfoliative toxin

TSST-1 (Toxic Shock Syndrome Toxin 1)

Enterotoxin

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

Is S. Aureus always harmful?

A

COMMENSAL 30% carry it, either in the nostrils or on the ski

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

Which AB is it commonly resistant to

A

MRSA

Resistant to methicillin= flucoxicillin

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

What can S. Aureus infect

A

Bone, joint, lung infections

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

What is the structure of the S. Aureus

A

Cell wall, cell membrane

Susceptible to penicillin treatment

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

What are panto valentina leucocidin

A

It is a virulence factor which makes the infection necrotising (tissue death)

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

What is the exfoliative toxin

A

Cuases cleave of the skin in the epidermis works on desmogleins so involves the same antigen as pempigus vulgaris

Causes LOCAL blisters in impertigo –> bollous impertigo

vs

auses SYSTEMIC scalded skin syndrome when the toxin gets into the blood.

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

What is TSST-1

A

Toxic shock syndrome 1 causes septicaemia type disease

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

What are enterotoxin

A

Food handler might have infected S. Aureus and an enterotoxin can get into the good and cause D and V in others

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

Where can S. Aureus cause infection

A

Bone joint lung infections

But focus of infection ften starts on the skin

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

When can staphylococcal lung infection occur

A

Often after flu (so deaths due to flue can be caused by this)

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

Manifestations of S. Aureus

A

Impetigo: subcorneal ayer

Folliculitis: mouth of hair follicle… can progress to abcess

Ecthyma: full thickness involvement of the epidermis, we see an (e.g. infected insect bite) NOT IN DERMIS

A carbuncle describes multiple abscesses next to each other, all coalescing.

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

What kind of skin infection does insect bite cause

A

Ecthyma ….

lesions look like firmly adherent crust on a background of erythema. The crust will not come off – the surface of the skin is dying. It commonly occurs after infected insect bites, or infected wounds.

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

What is it called if a folliculitis forms into abscess of hair follicle

A

Called boil

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

What is a carbuncle

A

Abscess of several adjacent hair follicles

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

Which S. Aureus infections are inthe spidermis and which in the dermis

A

Epidermis: Impetigo, folliculitis, ecthyma (might extend a tiny bit into the dermis)

Dermis: Boil and carbuncles

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

Feature of S. Aureus

A

Aureus= gold because the crust is golden

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

Common locatios for impetigo

What is bollous impetigo

A

It often occurs around the nose and mouth, but can occur anywhere (particularly groin/perineal region

Blistering with S. Aureus

Because of the exfoliative toxin
from S. Aureus (against that desmoglein antigen)

in addition to the impetigo which is just infection of the subcorneum and corneum

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

What can abscess start off as. How is it treated

A

Start as folliculitis treated with pus drainage

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

What can the exfoliative toxin from S Auerus casue

A
  1. Bollous impetigo

2. Staphylococcal scalded skin syndrome (DESQUAMATION of keratinocytes)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Who does Staphylococcal scalded skin syndrome occur in

A

Ages under 5

Because the immune system of children hasn’t developed properly so the infection can spread and cause widespread erythema and epithelial release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
How can you treat Staphylococcus scalded skin syndrome
With emollients + ABs (systemic infection)
26
What is the treatment for S. Auerus
Give flucoxicillin/clindamycin/erythromycin Topic for impetigo
27
What infection causes symphylis
Treponema pallidum
28
What type of bacterium is Treponema pallidum
Gram neg spirochete | Syph Spiro
29
What is coinfection with Treponema pallidum bad
Co-infection with syphilis increases the transmission of HIV
30
Phases of syphilis
``` Primary (3-8 weeks) Secondary (6-12) Latent Tertiary Congenital ```
31
Outline primary syphilis
Painless ulcer at inoculation site (Genital or oral) = chancre
32
Outline secondary syphilis
Disseminated infection | Generalised rash and lymphadenopathy
33
Outline latent syph
(no clinical signs)
34
Outline teriary syph
Skin, neurological and vascular manifestations
35
Outline congenital syph
Acquired perinatally | Early and late manifestations
36
What happens to the baby in congenital syph
``` Miscarriage Still birth Prematurity Rashes Brain and neurological problems Bone disease ```
37
Does syph involve palms and hands
Yes
38
What is a chancre
An ulcer.... primary syph often genital region Lasts a few weeks then disappears Can take a swap
39
What type of rash is seen in syph
In econdary syph Macropapular rash (can be just a few) Involves palms and soles
40
Why do brothels have red lights
Can't see the macropapular rash under it
41
What is Condyloma lata
NOT A WART But a wart type lesion seen in secondary syph Axilla and groin
42
Tertiary syphylis
Bone lesions Gummatous skin lesions Thoracic aneurysm Neurosyphilis
43
T/F Mother can pass syph onto the baby in a latent phase
T
44
Diagnosis of syph and treatment
For the chancre it'll be microscopy Otherwise look for antibody against syph Penicillin
45
How many human herpes viruses
8
46
What is HHV1, HHV2 and HHV3 What is the target cell
HHV1: HSV1 HHV2: HSV2 and HHV3: VZV macro-epithelial
47
What is the disease caused by HHV1, HHV2 and HHV3
1 &2: Oro-genital herpes Chickenpox shingles
48
Site of latency for HHV1, HHV2 and HHV3
NEURONS
49
What is HSV4. What is the target cell, and what is it also known as. Where is the latency
EBV Infection of B cell Infectious mono nucelosis B cell
50
What is HHV8 What is the target cell, and what is the site of latency
Karposi sarcoma associated herpes virus Target cell is lymphocyte Latency in B cells
51
What does HV1 and HV2 usually cause
General HSV 1= Oral coldsores HSV 2: Genital herpes
52
What does HHV5 cause, what is the target cell, disease and latency
CMV, Monocyte, epithelial cell, infectious mononucleosis type sndome Lymphocyte latency
53
What is HHV6 Target cell? disease? latency?
Roseola virus Lymphocyte latency and target cell Roseola
54
What is HHV 7 target cell and latency
T cell is target cell Pityriasis rosea is the disease Lymphocyte site of latency
55
What does KS affect and which patients
Endothelial cells of the lymphatics and affects HIV patients in partivular
56
Clinical presentation of Herpes simplex
Vesicular rash lasting two weeks on erythmatous base groups of vesicles which break up to form ulcers2 weeks then clears up
57
What can happen with primary HSV
Can be worse and form stomatitis (who mouth not just lips) hard to eat
58
What is stephen-hojnsons syndrom
Often cause by drug reaction can also get inflammation of mouth
59
What are herpetic lesions
Can be seen in eczema herpeticum, little punched out ulcers in the skin following the vesicle formation
60
What can latent HSV reactivate
Times of stress, sun exposure, other infection etc
61
HHV3 causes whatt
Chickenpox/ singles
62
What type of rash in chicken pox VCV
Looks like vesicles on erthymatous base scattered all ofver the body, most concentrated on the face, ess concentrated on the body and least concentrated on arms and legs Ask if they are feeling unwell if they are adults... found in mouth
63
Treatment for chikcen pox
Normally will get better by itself... can cause encephalitis
64
What is Herpes Zoster
This is shingles (i.e like chicken pox and herpes zoster both caused by VZV HHV3)
65
Distribution of rash in VZV
Comes after latency at times of stress or low immune function and spreads along 1 dermatome Vesicular
66
How do people feel with shingles
Can feel nothing or terrible
67
Does the rash in shingles cross the midline?
No ,because it's in dermatome
68
Can herpes zoster cross dermatomes
Yes it can partocilarly in immunosuppressed people like HIV
69
Why is involvement of the tip of the nose bad in herpes zoster
Because it can inidcate involvement of the nasociliary branch of V1 This could mean that the back of the eye is involved, and this needs more serious treatment to prevent blindness Acyclovir
70
Types of fungal infections
Superficial and deep (deep is in ID)
71
Types of superficial skin fungal infections
Dermatophytes Yeasts
72
Example of dermatophytes, where they grow
eg Trichophyton rubrum (often causes athletes foot) Grow in keratin Skin hair and nails
73
How do dermatophytes grow
Long hyphae, grow from tip
74
Example of yeast and where they grow and how they grow
eg Candida Grow on warm wet surfaces single cell and bud Groin genitals under breast, axilla and groins
75
What is tinea unguium and what is it usually caused by What does it look like
This is the disease not the fungus Funal infection of the nails Usually caused by dermatophytes but sometimes yeast Yellow and crumbly
76
How to treat tinea unguium
Anti-fungal IV Topical probably won't work because it's deep in the nail
77
Cause of tinea capitis
Funal infection on the head
78
Who does tinea capitis occur on
Kids not adults At around puberty sebum produces antifungals Agro-caribbean kids due to shape of hair shaft makes suceptible to fungal infection
79
Types of lesion in tinea capitis
Kerion (abscess type lesion, well defined) ... dermatophyte Diffuse across scalp
80
Waht is fungal superficial infection of the hadn called
Tinea mannum Vets get it and kids with pets. Fungus transferred from the pet to the kid
81
What is tinea curis
Fungal infection of skin around the groin Not involving scrotum
82
Tinea facei
Funal infection of the face (on chin may be pet related)
83
Dandida intertrigo
Yeast infection often on top of somme eczema Some satellite regions Wet rash Intertrigo means inflammation within a body crease
84
Tinea pedis
Between toes (usually due to Trichophyton rubrum (athletes foot)
85
An area that tinea doesn't appear on
The scrotum, only the groin
86
Treamtnet of the superficial fungal infections
SKIN only -> topical cream (clotrimazole antidngal) HAIR OR NAIL --> the infection has gone deeper and needs tablet... it goes down the hair follice
87
Latin name for scabies
Sarcoptes scabei A mite
88
Where do scabies burrow
Deep in surface off epidermis Finger, axillae, genital area, insteps of the feet Widepsread itchy rash
89
What happens after the scabies infectin
After the burrows, two weeks later eczema reaction ot the eggs and faeces
90
Does tinea infection include yeast
Strictly speaking no, just dermatophyte General fungal nail infection (ie yeast or dermatophyte= onchynychhya mycosis) Dermatophyte infection nail= tinea unguium

Rob's Microbiology MCD (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions