Superficial and necrotic infections 3 Flashcards Preview

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Flashcards in Superficial and necrotic infections 3 Deck (25)
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1
Q

what is the most common superficial skin infection?

A

impetigo

2
Q

typical occurrence age of impetigo

A

any age but common in pre school

3
Q

what can cause impetigo

A

minor trauma

4
Q

where do we carry the bacteria which can cause it

A

the nasal passage which migrates to other parts of the face

5
Q

typical causative organism?

a less common cause?

A

typically S.aureus

can be GAS but this is less common

6
Q

summer has _____ cases than winter. why?

A

more

association with insect bites

7
Q

2 forms of impetigo

which is more common

A

bullous impetigo (30% of cases) and non bullous (70%)

8
Q

difference in clinical presentation of bullous and non bullous impetigo

A

bullous tends to see small blisters containing a clear yellow liquid on the skin
non-bullous are flatter crusts on the skin surface

9
Q

universally bullous is caused by?

A

S.aureus

10
Q

can all S. aureus cause bullous impetigo? explain

A

no

must produce exfoliative toxin A

11
Q

what must the S.aureus be specific for to cause bullous impetigo

A

desmoglein 1

it cleaves desmoglein 1 and causes detachment of the skin layer to aid movement to deeper layers

12
Q

desmoglein 1 is predominantly expressed where? what is expressed in the lower layers? effect?

A

outer skin layers- anchors the two layers to the deeper stratum

D-3 is more abundant in the lower layers

13
Q

why doesn’t S.aureus effect the deeper layers

A

produces exfoliative toxin A which is specific for D1 but not D3 in the deeper layers

14
Q

TF impetigo is self limiting

A

true if its uncomplicated

15
Q

how to treat mild localised impetigo

A

fusidic acid for 5d TDS

16
Q

in mild localised treatment of impetigo by fusidic acid, its use is _____ spectrum

A

staphylococcal agent- narrow spectrum

17
Q

for bullous or widespread impetigo what do we treat it with?

A

oral flucloxacilin for 7d QDS or clarithromyin if penicillin allergy

18
Q

flucloxacillin drug class?

A

beta lactam

19
Q

what to do if after treatment there’s no improvement to impetigo?

A

swab for microbiological cause

can give something more specific

20
Q

what is a generalised form of bullous impetigo that’s very rare?

A

staphylococcal scalded skin syndrome

21
Q

why does SSSS not occur in adults

A

renal function can remove the toxin

22
Q

difference in toxin in the SSSS and impetigo

A

same toxin but its more widespread

23
Q

children with SSSS: their temperature regulation and fluids are affected how?

A

poor temperature regulation and fluid loss

24
Q

in SSSS where is the primary infection site typically? what does this mean for testing for the causative bacteria?

A

somewhere distal to the skin

wouldn’t find the bacteria by taking a skin swab

25
Q

how does SSSS occur?

A

toxin A is in the blood io has a more wide spread effect