skin and soft tissue

Question 1

what is an enanthem

Answer 1

lesion on mucosal membrane

Question 2

what is an ecchymosis

Answer 2

large area of bruising

Question 3

how is dry skin a risk factor for skin infections

Answer 3

subaceous fluids keep pH low, together with fatty acids help to inhibit microbial growth

Question 4

what microbes are more commonly responsible for skin infections in diabetics

Answer 4

s aureus
grp b strep
anaerobes
g -ve bacilli

Question 5

what microbes are more commonly responsible for skin infections in IVDU

Answer 5

MRSA

Ps aeruginosa

Question 6

is staph aureus an anaerobe aerobe or facultative organism

Answer 6

facultative

Question 7

what is MRSA usually resistant against

Answer 7

flucloxacillin

Question 8

name a few antibiotics that can be used against MRSA

Answer 8

vancomycin
daptomycin
tetracycline
clindamycin

Question 9

what does crepitus in a skin infection indicate

Answer 9

gas gangrene

Question 10

in severe infections, what can thrombocytopaenia be an early indicator of?

Answer 10

DIC

Question 11

what blood marker will be different in rhabdomyolisis

Answer 11

hypocalcaemia

Question 12

order by depth of infection

erysipelas
necrotising fasciitis
ecythema
cellulitis
impetigo

Answer 12

impetigo
erysipelas
ecythema
cellulitis
necrotising fasciitis

Question 13

what is impetigo caused by

Answer 13

staph aureus

Question 14

how deep does erysipelas go to

Answer 14

upper dermis

Question 15

where does erysipelas usually affect

Answer 15

face cheeks, periorbital region

Question 16

what causes ecythema

Answer 16

group a beta haemolytic streptococcus

Question 17

what do these affect? - folliculitis, furuncles, carbuncles

Answer 17

hair follicles

Question 18

name 2 organisms that can cause cellulitis

Answer 18

strep pyogenes

staph aureus

Question 19

clinical features of cellulitis

Answer 19

hot swollen tender skin

usually unilateral and on lower limbs

Question 20

systemic features of cellulits

Answer 20

fever
sweats
rigors

Question 21

antibiotic used for cellulitis

Answer 21

flucloxacillin

Question 22

describe 2 types of necrotising fasciitis

Answer 22

type 1 is polymicrobial

type 2 is monomicrobial

Question 23

what virulence factor causes necrotising fasciitis to be so severe

Answer 23

enzymes that break down tissue e.g.

streptokinase
hyaluronidase

Question 24

why is the fascia more easily infected

Answer 24

poor blood supply

Question 25

clinical features of necrotising fasciitis

Answer 25

``` erythema with diffuse borders edema severe pain blisters rapid progression systemic features skin anaesthesia skin necrosis ```

Question 26

treatment for necrotising fasciitis

Answer 26

surgical treatment amputation antibiotics

Question 27

bacteria responsible for trauma-related gas gangrene

Answer 27

clostridium perfringens

Question 28

what are 2 structures within bone that can serve as conduits for infection in and out of the bone

Answer 28

volkmann's and haversian channels

Question 29

why is chronic osteomyelitis very hard to treat

Answer 29

bacteria is embedded into the bone matrix

Question 30

difference between pyogenic and non-pyogenic osteomyelitis

Answer 30

pyogenic OM involves accumulation of neutrophils, usually bacterial caused non-pyogenic OM does not involve neutrophilic response, caused by organisms like TB, aspergillus etc.

Question 31

3 routes of non-iatrogenic OM?

Answer 31

haematogenous contiguous trauma

Question 32

in IVDU what route of OM is more likely

Answer 32

haematogenous

Question 33

2 ways of acuiring iatrogenic OM

Answer 33

post-operative | device related

Question 34

what is engrafting and why is it bad

Answer 34

when fibrotic tissue forms around new prosthetic joint/shaft, biofilm that forms inside has poorer blood supply due to fibrosis; restrict immune response and antibiotic efficacy

Question 35

what is sequestrum and involucrum

Answer 35

sequestrum = necrotic segment within the bone involucrum = new bone formation outside of periosteum in response to bone damage due to infection

Question 36

in which kind of OM is sequestrum more likely to be found?

Answer 36

chronic OM

Question 37

in acute OM, bone can rapidly necrose causing delibitating pain and pathological fractures - T or F?

Answer 37

False - necrotic bone segment is more commonly found in chronic OM

Question 38

pus discharging sinus is an early sign of OM - T or F?

Answer 38

False - it is a late sign of chronic OM

Question 39

no.1 most common organism causing OM

Answer 39

stpah aureus

Question 40

in children, which part of the body is most likely to be affected with osteomyelitis?

Answer 40

metaphysis, just under the growth plates

Question 41

in acute haematogenous OM for adults, where is it most likely to be affected?

Answer 41

vertebral bodies

Question 42

in spinal osteomyelitis, 2 adjacent vertebrae and the disc in between is a common pattern of infection - T/F? and why?

Answer 42

True - because they are usually supplied by the same 1 spinal artery

Question 43

recent infection can predispose you to OM - T or F

Answer 43

T

Question 44

why is a urinary catheter a risk for OM?

Answer 44

because bladder venous plexus drains into the spinous veins

Question 45

what is the most common route of infection in chronic pyogenic osteomyelitis?

Answer 45

haematogenous

Question 46

what imaging is best for suspected OM?

Answer 46

xrays for quick assessment | CT and MRI are best to show sequetreum/involucrum/soft tissue/joint pathology

Question 47

most common antibiotic used for OM

Answer 47

flucloxacillin