Skin infections Flashcards
What is cellulitis?
Bacterial infection of the deep subcutaneous tissue. [pts]
What causes cellulitis?
Beta-haemolytic strep eg Strep. pyogenes
Staph. aureus, sometimes MRSA
Normally enters through abrasion or ulcer
Give 3 risk factors for cellulitis.
Immunosuppression
Wounds/ trauma
Leg ulcers
Athlete’s foot
Describe the presentation of cellulitis.
Local inflammation - red, hot, swollen, painful
Systemically unwell - fever
Often affects lower leg, spreading upwards; or face
May blister - especially if there is oedema.
[pts]
Describe the management of cellulitis.
Antibiotics - flucloxacillin and phenoxymethylpenicillin
If widespread disease, give IV abx for 3-5 days then 2 weeks oral therapy
If recurrent, give prophylactic low-dose phenoxymethylpenicillin BD.
[pts]
What is necrotising fasciitis?
A fulminant, rapidly spreading infection of the deep fascia, associated with widespread tissue destruction (necrosis). [pts]
What is the pathophysiology of NF?
There are two types/causes:
1. Anaerobic and aerobic bacteria following abdominal surgery or in diabetics
2. Group A strep, arises spontaenously in healthy people.
Infection tracks rapidly along the tissue planes.
Give 3 risk factors for NF.
Abdomical surgery
Diabetes
Immunosuppression
Describe the signs and symptoms of NF.
Severe pain out of proportion at site of initial infection, rapidly followed by tissue necrosis
Systemically unwell
As infection spreads so does erythema, pain +/- crepitus.
What findings on investigation would support the diagnosis of NF?
Fever, toxicity and pain out of proportion
High CRP and WCC
What are the main complications of NF?
Multi-organ failure; high mortality
Describe the management of NF.
Aggressive and prompt abx:
Group A strep –> benzylpenicillin, clindamycin
Mixed bacteria –> broad-spec: vancomycin, ceftriaxone and metronidazole
Urgent surgical debridement (removal of unhealthy tissues), amputation if necessary.
