wk 10 - bone and soft tissue infections

Question 1

erysipelas is

Answer 1

bacterial infection of the upper half of dermis

Question 2

cellulitis is

Answer 2

bacterial infection of the lower half of dermis into the subcutaneous fat

Question 3

if someone has systemic symptoms where should you refer to?

Answer 3

emergency department

Question 4

patient characteristics of cellulitis and erysipelas (differences)
Age
How fast does it progress
Line of demarcation
Organism

Answer 4

cellulitis
-occurs in middle age/older
-slowly increases
-line of demarcation ill defined
-organism: strep pyogenes 2/3, staph aureus 1/3

erysipelas
-occurs in children
–rapidly
-clear line of demarcation
-can have vesicles
-organism: strep pyogenes

Question 5

risk factors of skin infection

Answer 5

impaired barrier function
weakened immune system
iV drug use

Question 6

complications of cellulitis

Answer 6

progression to

lymphangitis
abscess formation
gangenous cellulitis
necrotising fascitis
sepsis
death

Question 7

treatment guidelines for erysipelas without systemic features

Answer 7

referral for IV:

1. phenoxymethylpenicllin
   OR
2. brocaine benzylpenicillin

if delayed nonserve hypersensitivity
2. cefalexin

if immediate nonsevere/severe or delayed severe
2. clindamycin

Question 8

signs in cellulitis to be concerned about

Answer 8

soft, fluctuant areas - abscess formation

red streak from area of cellulitis or fast spreading of redness

significant pain not aleviating by medications

inability to move joint because of pain

patients with diabetes, cancer, immunosuppressant

systemically unwell

Question 9

main role of podiatrist in management /prevention of these infections?

Answer 9

maintain barrier function of the skin

Question 10

spetic arthritis organisms involved and how many joints affected?

Answer 10

presents usually as single joint infection

organisms:
1. staph aureus or
2. gonorrhoeae (recent STI?)

Question 11

how to diagnose septic arthritis/investigations

Answer 11

joint aspiration for:
- cell count
- crystals
-MC and S

blood culture

radiograph

Question 12

what monoarthritis presenting condition should be considered in ATSI populations

Answer 12

acute rheumatic fever

Question 13

management of septic arthritis in hospital

Answer 13

-drainge of pus and joint irrigation

-synvoectomy to remove pathogens and help with diffusion of antibiotic into joint

-early treat will reduce joint damage

Question 14

osteomyelitis

Answer 14

inflammation/ infection of the bone or bone marrow

organism: staph aureus can also by fungi

red fag: probe to bone in ulcers

Question 15

signs and symptoms of osteomyelitis (acute v chronic)

Answer 15

acute
-pain at site
fevers

chronic
-weight loss
-prolonged systemic signs

Question 16

radiographic signs of osteomyelitis

Answer 16

deep soft tissue swelling

periosteal reaction

cortical irregularity

bone demineralisation

Question 17

how does infection get to bone

Answer 17

20% of people dont carry staph aureus

60% are intermittent carriers

20% of people always carry staph aureus (reservoirs) (1/5)

opportunistic infections- typically staph present in nose, is same as skin infection and osteomyelitic infections

Question 18

how does bacteria reach bone?

Answer 18

1. spread via blood (haematogenous)- infection in somewhere else in body
2. contiguous spread- overlying wound (common in podiatry- ulcers)
3. direct implantation secondary to trauma or surgery

Question 19

how can staph in the nose get to a distal site ?

Answer 19

doesnt have to be through contact but can be via blood

bacteria that cna remain undetected and not raising and inflammatory response can do this

they can also convert to SCV cells to tolerate antimicrobials

Question 20

can staph aureus enter osteophytes?

Answer 20

yes as a SCV cell, which acts as a resivoir for pressitent infection. often when the host is compromised is when they revert back to staph aureus

Question 21

if someone is immunocompromised what does that mean for infections

Answer 21

they are at high risk and their body is unlikely to provide large signs to show that there is an infection, more discrete signs

Question 22

IV antibiotics is necessary when?

Answer 22

adults with two or more of the follow systemic symptoms of infection

-temp more than 38deg or less than 36 deg

-heart rate more than 90bpm

-respiratory rate more than 20 breaths a min

-white cell count more than 12 x 10^9 L or less than 4 x 10^9L

-contact GP and refer to hospital for IV

Question 23

local signs of infection

Answer 23

tenderness
warmth
redness - erythema
swelling

probe to bone-osteomyelitis

Question 24

if someone has an infected diabetic foot and youre deciding what antibiotics to use where would you go?

Answer 24

IWGDF guidelines

Question 25

process of diabetic foot infection and antibiotic treatment

Answer 25

swab and send for MC and S refer to gp for renal function, BGLs consider medical history (allergies, drug interactions) IWGDF guidelines based off degree of infection -empiracal therapy -directed therapy refer to hospital if there is -systemic signs of infection -unresolving infection -osteomyelitis

Question 26

diagnosing osteomyelitis and monitoring

Answer 26

probe to bone test bone biopsy- gold standard but rarely done radiograph blood tests elevated: -ESR -CRP -WCC culture monitoring -blood tests and renal function tests

Question 27

IWGDF guidelines on determining if there is an infection

Answer 27

needs to have two of the following features -local swelling/induration -erythema extending more than 0.5 -local tenderness/pain -local warmth -purulent discharge

Question 28

IWDGF gudelines on infection classification (mild, mod, sev)

Answer 28

mild- only the skin/subcutaneous tissue erythema extends no more than 2cm no systemic features mod- involves structures deeper than skin/subcutaneous tissue (muscle, bone, tendon, joint) or erythema extends more than 2cm. no systemic features sev- systemic inflammtory response syndrome

Question 29

how long should antibiotic treatment take for mild/mod infection

Answer 29

duration: 1-2 weeks for mild/mod -infection should be reolsved by this time but not wound pathology results may change antibiotic treatment

Question 30

key steps to assessing and treating an infection

Answer 30

1. rule out serious pathology -refer to hospital if theres signs of septic arthritis ostoemyleities unresolving infection severe infection that requires IV systemic symptoms (2 or more signs) 2. is there signs of infection (2 or more) 3. what degree of infection (mild, mod, sev)- wound?no wound? 4. TG or IWGDF guidelines for treatment 5. management -swab -GP blood tests to diagnose/monitor -empiracal treatment based of EBP -directed therapy

Question 31

what type of antibiotic for mild, mod,sev dibetic foot infections

Answer 31

mild-oral mod-IV sev-IV

Question 32

antimicrobial resistance types

Answer 32

1. multi-drug resistant- non susceptible to 1 or more agents in 3 or more categories 2. extensively drug resistant - non susceptible to 1 agent in all but less than 2 categories 3. pan-drug ressitant - non susceptible to all approved anti microbial agents (eg pseudomonoas)

Question 33

ways that selective pressure has caused evolution of bacteria

Answer 33

1. indiscriminate use of antibiotics 2. insufficient dosages 3. insufficient length of courses

Question 34

other ways resistance has occurred

Answer 34

1. broad spectrum 2. empiracal treatment without switching to narrow 3. non compliance 4. inadequate dosage/length 5. easy access to prescription 6. hospital/nursing homes allowing spread 7. over exposure to antibiotics 8. animal husbandry- antibiotics on farm animals

Question 35

types of antimicrobial resistance in humans

Answer 35

1. innate - species are naturally resistant 2. acquired- bacteria that was once sensitive to a drug becomes resistant (gene codes for resistance is transferred from one bacterium to another by mutation or transfer genetic material)

Question 36

mechanisms of antimicrobial resistance

Answer 36

1. enzymes produced by bacteria destroy the drug 2. bacterial cell walls become impermeable to a drug or rapidly removed 3. drug binding sites within abcteria become altered 4. alternative metabolic pathway in bacteria using enzymes not affected by the drug

Question 38

How long do corticosteroids work for

Answer 38

Everyone responds differently but usually around a few weeks to just over a month

Question 39

How do you store corticosteroids in clinic

Answer 39

S4 med- Secure location Room temperature Only endorsed prescribers can access location Documentations for purchasing for 2 years