Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Dermatology > Microbiology of skin infections > Flashcards

Microbiology of skin infections Flashcards

1
Q

What are the skin’s defences against infection?

A

Intact skin is much less likely to become infected
Dry - dessication of microorganisms
Sebum - fatty acids inhibit bacterial growth
Competitive bacterial flora
Concept of resident and transient flora

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

What are common competitive bacterial flora on the skin?

A

Staphylococcus epidermis
Corynebacterium (diptheroids)
Propionibacterium

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

How are bacterial skin infections diagnosed?

A

Swab of lesions if surface broken
Pus or tissue if deeper lesion
+/- blood cultures if appropriate

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

How will staph auerus coagulase?

A

Golden

Positive coagulase

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

What are the different species of alpha haemolytic streptococcus chains?

A

Step pneumoniae

Strep viridans

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

What are the different species of beta haemolytic streptococcus chains?

A

Group A strep (throat, skin infection)
Group B strep (neonatal meningitis)
Group C, G strep

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

What are the different species of non haemolytic streptococcus chains?

A

Enterococcus (gut commensal, UTI)

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

What are the different species of coagulase positive staphylococcus clusters?

A

Staph aureus (wound, skin infection)

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

What are the different species of coagulase negative staphylococcus clusters?

A

Staph epidermis

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

In what air conditions will staphylococcus grow?

A

Aerobic and facultatively anaerobic

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

What are some virulence factors that staphylococcus aureus can produce?

A

Enterotoxin - food poisining
SSSST - staphylococcal scalded skin syndrome toxin
PVL - panton valentine leucocidin

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

What bacterial skin infections can staph aureus cause?

A 
Boils and carbuncles 
Infected cuts 
Cellulitis
Infected eczema
Impetigo
Wound infection 
Staphylococcal scalded skin syndrome
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the treatment options for MRSA?

A

Skin or soft tissue - doxycycline, co-trimoxazole, clindamycin
Blood stream - vancomycin

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

What infections are staphylococcus epidermis bacteria associated with?

A

Implanted artifical material such as artifical joints, artifical heart valves, IV catheters

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

In what air conditions will streptococcus species grow?

A

Aerobic and faculatively anaerobic

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

What bacterial skin infections can strep pyogenes (group A strep) cause?

A 
Infected eczema
Impetigo
Cellulitis
Erysipeas
Necrotizing fasciitis
17
Q

How are strep. pyogenes infections treated?

A

Penicillin but can also be treated with flucoxacillin

18
Q

How will necrotizing fasciitis present?

A

Patient in excrutiating pain disproportionate to the wound

Needs surgery ASAP

19
Q

What is necrotizing fasciitis?

A

Bacterial infection spreading along fascial planes below the skin surface causing rapid tissue destruction - little to see on skin surface but severe pain

20
Q

What are the different types of necrotising fasciitis?

A

Type 1 - mixed anaerobes and coliform, usually post-abdominal surgery
Type 2 - group A strep infection

21
Q

What organisms are worth treating in regards to leg ulcers?

A

Strep pyogenes (group A), staph auerus
Other beta-haemolytic streptococci (B, C, G)
Anaerobes in diabetic patients

22
Q

What would make a leg ulcer worrying?

A

If it has been there for more than 2 months and is over 2cm then you should be concerned about osteomyelitis

23
Q

What is tinea?

A

Ringworm

24
Q

How do dermatophytes enter the skin?

A

It enters abraded or soggy skin

25
Q

How do the funal hyphae spread?

A

Via the stratum corneum

Infects keratinisied tissues only

26
Q

How do fungal infections present?

A

Ring like structures

27
Q

What fungus causes the most tinea infections?

A 
Trichophyton rubrum 
THEN 
Trichophyton mentagraphytes
THEN 
Microsporum canis
28
Q

How are dermatophyte infections diagnosed?

A

Clinical appearance
Woods light
Skin scraping

29
Q

How are small areas of fungally infected skin and nails treated?

A

Clotrimazole

30
Q

How are funal scalp infections treated?

A

Terbinafine - need to monitor LFTs

31
Q

Where does candida cause skin infections?

A

In the skin folds where the area is warm and moist - this is called candidia intertrigo

32
Q

How is candidia intertrigo treated?

A

Clotrimazole cream

Oral fluconazole

33
Q

What causes scabies?

A

Sarcoptes scabeiei

34
Q

What is the most infectious form of scabies?

A

Chronic crusted scabies

35
Q

What is the incubation period of scabies?

A

Up to 6 weeks

36
Q

What are the symptoms of scabies?

A

Intensely itchy rash affecting finger webs, wristss and genital area

37
Q

How are scabies treated?

A

Malathion lotion applied overnight to whole body and washed off next day

38
Q

What patients need single room isolation?

A

Group A strep infection
MRSA
Scabies

Dermatology (24 decks)

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