Revision - Cellulitis Flashcards
What are the 3 most common organisms causing cellulitis?
1) Staph. aureus
2) GAS (Strep. pyogenes)
3) GCS (Strep. dysgalactiae)
A golden-yellow crust in cellulitis indicates which causative organism?
Staph. aureus
What classification system is used to guide management of cellulitis?
Eron classification
Describe the Eron classification
Class I - no systemic toxicity or comorbidity
Class II - no systemic toxicity or comorbidity
Class III - significant systemic toxicity or significant comorbidity
Class IV - sepsis or life-threatening infection
What Eron classification indicates admission for IV Abx?
Class III & IV
What is the most common pathogen causing cellulitis?
Streptococcus:
1) Strep. pyogenes
2) Group A beta-haemolytic streptococci
Is a cellulitic rash more likely to be unilateral or bilateral?
Unilateral
What should a rapidly progressive and blistering rash prompt consideration of?
Necrotising fasciitis
What is cellulitis mx guided by?
Eron classification
1st line mx of cellulitis (Eron classification I)?
Oral flucloxacillin
Oral clarithromycin, erythromycin (in pregnancy) or doxycycline is recommended in patients allergic to penicillin.
1st line oral abx in pregnancy?
Oral flucloxacillin
Oral erythromycin (if penicillin allergic)
What is usually the 1st choice Abx for cellulitis near the eyes or nose?
Co-amoxiclav
1st line Abx in severe cellulitis?
Oral/IV co-amoxiclav, oral/IV clindamycin, IV cefuroxime or IV ceftriaxone
Lack of what vaccination is a risk factor for orbital cellulitis?
Hib
What is necrotising fasciitis?
A severe and rapidly progressive soft tissue infection that causes necrosis of the SC tissues and fascia, sometimes also affecting the muscle.
How can NF be categorised?
Categorised depending on the causative organism
What are the 4 types of NF?
Type I –> polymicrobial (i.e. multiple anaerobic species)
Type II –> monomicrobial (Strep. pyogenes)
Type III –> monomicrobial (Clostridium species)
Type IV –> fungal (Candida)
What is the most common type of NF?
Type I (polymicrobial)
What organism causes type II NF?
Strep. pyogenes
Who does Type II NF typically occur in?
Younger patients w/ a history of trauma
What organism causes type III NF?
Clostridium species
Who is type III NF typically found in?
IVDU
What organism is type IV NF caused by?
Candida
Who is type IV NF typically seen in?
Immunocompromised
What is gas gangrene?
Form of NF caused by C. perfringens –> resulting in gas being produced by the bacteria within the tissue.
What is the only definitive management of NF?
Surgical debridement
What is the site most commonly affected by NF?
Perineum (Fournier’s gangrene)
is clarithromycin safe in pregnancy?
No - but erythromycin is
1st line abx in pregnancy if patient is penicillin allergic?
Oral erythromycin
Diagnosis of cellulitis?
Clinical - no further investigations are required in primary care
