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Flashcards in MSK Infections Deck (31)
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1
Q

what is osteomyelitis

A

inflammation or bone and medullary cavity usually in one of long bones

2
Q

what are symptoms of osteomyelitis

A

fever, chills, fatigue, lethargy or irritability classic signs of inflammation include local pain, swelling or redness if you can see tendon or probe bone - deffs osteomyelitis

3
Q

what are most common causes of osteomyelitis in newborns (<4 months)

A

staph aureus

enterobacter sp

group A and B strep

4
Q

what are most common causes of osteomyelitis in children (aged 4 months to 4 years)

A

staph aureus

group A strep

haemophilus influenzae

enterobacter sp

5
Q

what are most common causes of osteomyelitis in children / adolescents (aged 4 years to adult)

A

staph aureus (80%)

group A strep

H influenzae enterobacter sp

6
Q

what are most common causes of osteomyelitis in adults

A

staph aureus

occasionally enterobacter or streptococcus

7
Q

what are most common causes of osteomyelitis in sickle cell anaemia patients

A

staph aureus most common

salmonella species common and unique to SCA

8
Q

what causes prosthetic joint osteomyelitis

A

mostly staph aureus or epidermis

rarely: propionibacterium acnes (upper limb), e coli, pseudomonas aeruginosa

9
Q

what are causes of contiguous osteomyelitis

A

open fractures diabetes / venous insufficiency

10
Q

what are haematogenous causes of osteomyelitis

A

PWID (viridans common here, pseudomonas, candida in heroin, eikenella corrodens in needle lickers and M tuberculosis)

Dialysis

Gauchers disease (lysosomal storage disorder)

Vertebral (most common, associated w epidural, psoas abscess, PWID, IV site infection, GU infection, SSTI, post op)

11
Q

what causes skeletal osteomyelitis

A

vertebral TB (potts) = often no systemic symptoms

kids = check reduced receptors for IFN-gammma R1, IL12 beta 1

adults = offer HIV test

causes gibbous deformity

12
Q

how is osteomyelitis diagnosed

A

indirect (scan) or direct (bone biopsy is gold standard)

might want to do MRI to make sure

13
Q

how is osteomyelitis treated

A

debridement / drainage / removal of joint

antibiotics for 6 weeks = do not give empirically, wait for results

acute = flucloxacillin IV (2 weeks) then 4 weeks oral therapy

chronic = oral flucloxacillin (if MRSA or allergy = doxycycline or co-trimoxazole)

if coliforms = seek advice

14
Q

what is septic arthritis

A

inflammation of joint space caused by infection

15
Q

what causes septic arthritis

A

can be blood borne organisms, extension of local infection, or by direct inoculation (following injection of joint or trauma)

*previously damaged joints ie RA more susceptible

16
Q

what are causative organisms in septic arthritis

A

staph aureus

streptococci

coagulase -ve staph (epidermis) = prosthetic joint

neisseria gonorrheae = sexually active patients

haemophillus influenze = pre school, not common now

17
Q

what are symptoms of septic arthritis

A

severe pain, red, hot, swollen plus limited movement

18
Q

how is septic arthritis diagnosed

A

clinical picture

joint fluid = yellow-green due to elevated nucleated cells

blood culture if pyrexial

exclude crystals

19
Q

how is septic arthritis treated

A

presumptive treatment to cover staph aureus = flucloxacillin clindamycin if allergic

if <5 years old, add cefriaxone for H influenzae cover

adjust when organisms confirmed

20
Q

what is knee bursitis

A

inflammation of small fluid filled sac (bursa) situated near knee joint

21
Q

what is pyomyositis

A

bacterial infection in skeletal muscles which results in pus-filled abscesses

22
Q

what causes pyomyositis

A

90% staph aureus

perineum = GNB

immunosuppressed = pseudomonas

B haemolytic strep

enterococcus clostridial infection = contaminated wounds (inject heroin)

23
Q

what are symptoms of pyomyositis

A

common in tropical areas but can also occur in temperate zones

24
Q

how is pyomyositis diagnosed

A

pus discharge culture and sensitivity

xray to rule out osteomyelitis

creatine phosphokinase (when muscle damaged, this leaks into blood)

MRI useful

25
Q

how is pyomyositis treated

A

drained surgically and antibiotics

26
Q

what is tetanus

A

serious muscle bacterial disease that is a neurotoxin (binds to inhibitory neurons, preventing release of neurotransmitters)

27
Q

what causes tetanus

A

clostridium tetani

(gram +ve anaerobic bacillus rods, spores found in soil, house dust, animal intestines, gardens etc, incubation time is 4 days - several weeks)

28
Q

what are symptoms of tetanus

A

painful contractions (particularly of jaw and neck) known as lock-jaw

29
Q

how is tetanus diagnosed

A

clinical picture (spastic paralysis)

culture (very hard! perhaps terminal spore - drumstick shape)

30
Q

how is tetanus treated

A

surgical debridement

antitoxin

supportive measures

antibiotics = penicillin / metronidazole

booster vaccination = toxoid

31
Q

how can tetanus be prevented

A

toxoid vaccine (2, 3, 4 months)