Skin and soft tissue infection Flashcards
What is impetigo
A common childhood skin condition that affects the face, legs and exposed areas.
Show red patch with central fluid
what is impetigo cause by
staphylococcus aureus
Streptococcus pyogenes (group a strep)
Treatment for impetigo
Flucloxacillin
* Erythromycin is allergic to penicillin
Complication for impetigo
Staphylococcal scalded skin syndrome (SSSS)
larger vesicles & serious forms of impetigo
secrete epidermolytic toxins
diagnosis for impetigo
visual diagnosis
swab lesion for culture & sensitive testing
what is abscesses
a localised collection of pus
types fo abscesses
Furuncle
- occurs in the hair follicles
- cause by common bacteria like S.aureus
- swelling with central pus collection
Carbuncle
- involve many follicles or glands
- create multiple discharging heads
What is the context that is within the abscess?
mostly fluid + neutrophils + causative organisms
identify the cause of organisms in the following types of abscesses
- skin abscess
- buttock abscesses
- deep tissue abscesses
- skin abscess
S.aureus - buttock abscesses
obligate anaerobes + other gut flora - deep tissue abscesses
obligate anaerobes, +/- streptococci, +/- S.aureus
What are the treatments for abscesses
Incision and drainage
apply antibiotics
(penicillin/flucloxacillin + metronidazole)
Diagnosis for abscesses
microscopy for deep tissues
culture bacteria including the anaerobic
sensitivity testing
what is the condition fo cellulitis
acute spreading infection under the skin
clinical appearance of cellulitis
hot
red
swollen
painful
fever
complication of cellulitis
Spread into deeper soft tissue e.g. fat and muscle
which can cause septicaemia
organisms causes for cellulitis
S.aureus
Group A streptococcus
haemolytic strep B, C, G
Enterobacteriaceae and anaerobes in buttock cellulitis
diagnosis of cellulitis
clinical appearance
- blood culture
- biopsy (only done if treatment failure)
- ASO (anti-streptolysin O) if culture negative
*Swabs have no effect if there is no presence of infected
Treatment for cellulitis
Antistaphylococcal - flucloxacillin
+
Antistreptococcal - penicillin
what is the type of cellulitis that occurs on the head and neck only
generate more superficial than cellulitis
Erysipelas
cause by Group A strep
(sometimes group G but rare cases)
Where is the site of infection that happens the most for necrotising fasciitis?
Connective tissue
fat
muscle
the complication of necrotising fasciitis
extensive tissue destruction with loss of function
risk of overwhelming infection septicaemia and death
organisms cause necrotising fasciitis
streptococci group ABCDF
staphylococcus aureuss
anaerobic Gram + clostridial species
anaerobic Gram - Bacteroides species
What is the causation of necrotising fasciitis
pathogenes encounter ischaemic tissue
lytic toxins and toxin that promote spreads
the predisposition of necrotising fasciitis
old age (weaker immunity)
diabetes (plenty of nutrients in sugar and cultivation)
poor peripheral circulation
immunosuppression
diagnosis for Necrotising fasciitis
microscopy of fluids and tissue samples
aerobic and anaerobic culture of samples
blood culture
sort of treatment can be used on necrotising fasciitis
surgical excision of affected tissue
antibiotics
- cidal
- protein inhibitors
What are the characteristics of puncture wounds
small or closed surface
deep cuts or wounds
can get contamination from
soil: tetanus risk
inorganic foreign body
Why puncture wounds are listed as a severe condition, and what are their complication to further condition?
cellulitis
abscess formation
tetanus - infection that cause muscle spasm and tension
osteomyelitis - inflammation of bone infection
What to do to prevent the future worsening of puncture wounds?
clean
remove damaged tissue and foreign body
vaccinate again tetanus
antibiotic cover
What is the difference between animal bites in a puncture wound
same risk as the puncture wound
Capnocytophagia canimorsus for Dogs
Pasteurella multocida –> Cats
*Both are pyogenic organisms
+ streptococci, staphylococci and anaerobes common to most mammalian oral flora
diagnosis and management for animal bites
culture of a swab of the site
microscopy and culture of any subsequent abscess
clean, remove and antibiotics and anaerobic cover
a condition that has skin ulcerates due to prolonged pressure
Pressure sores
risk factors that can cause pressure sores
faecal urinary incontinence
underlying fracture
malnutrition
What organisms favour the colonisation in pressure sores
S.aureus
Group G streptococci
Pseudomonas
factors that can increase the rate of surgical wound infection
length of operation
subsequent haematoma
the general health of the patient
wound classification
how would you deal with if a surgical wound infection is found?
do laboratory investigations
microscopy + culture
* infected tissues and infected fluids
do a blood culture if systemically unwell
