Soft tissue, bone, and joint infections Flashcards
What are some defences of the skin?
1) Exfoliation –> sloughing of the stratum corneum dislodges many adherent bacteria
2) Dryness
3) Acidic pH (5.5)
4) Low temperature
5) Sweat glands
6) Normal bacterial flora –> Compete for sites and nutrients
Name some micro-organisms that are present on the skin….
1) S. epidermidis
2) S. aureus
3) Micrococci
4) Diphtheroids
What is Staphylococcus aureus?
Gram positive cocci and coagulase positive, golden colonies.
Acquired resistance to beta lactam antibiotics – MRSA
What is Streptococcus pyogenes?
Group A streptococci.
Gram positive cocci.
Beta haemolytic.
Colonises the pharynx.
What is impetigo?
Superficial infection
Friable golden crusts over erythematous skin
More common in children
What is folliculitis?
Infection of hair follicles.
Common sites are groin and scalp.
Caused by S.aureus.
Treatment is flucloxacillin.
What is furunculosis?
Deep inflammatory lesion progressing from a folliculitis.
What is a carbuncle?
A red, swollen, and painful cluster of furuncle that are connected to each other under the skin.
Extend into the subcutaneous layer, multiple abscesses develop, separated by connective tissue.
What is an acute paronchia?
Skin infection arising from an nail.
What is cellulitis?
An inflammatory condition of the lower dermis and subcutaneous tissue caused by bacterial infection.
Commonly caused by S.Aureus (CA-MRSA).
What is erysipelas?
Infection involving the upper dermis and extends into the superficial cutaneous lymphatics.
Tend to have raised red skin.
Group A streptococci is the most common cause.
What is a surgical site infection (SSI)?
Infections that affect the surgical wound or
deeper tissues handled during the surgical procedure
resulting in local signs and clinical symptoms.
Infection must occur within 30 days (or 1 year if an implant was inserted).
What is septic arthritis?
Infection of the joint spaces.
Most common in a joint affected by rheumatoid arthritis or history of trauma.
What are the 3 ways in which bacteria can enter a joint?
1) Haematogenous route – most important
2) Direct inoculation via trauma
3) Arthritis with associated tendonitis
What is osteomyelitis?
Infection of the bone.
Can be infected via trauma/surgery or by haematogenous route.
Treated with flucloxacillin (OR vancomycin if MRSA).
