Skin

Question 1

Pathogens causing cellulitis

Answer 1

1. Staphylococcus aureus (causes purulent cellulitis)
2. Streptococcus pyogenes (non-purulent cellulitis)
3. Pasteurella multocida (secondary to dog and cat bites)

Question 2

Predisposing factors to cellulitis

Answer 2

1. Chronic venous or arterial ulcers
2. Primary skin disease - eczema, psoriasis, dermatitis
3. Minor trauma, recent surgery
4. Leg oedema - RHF, venous imcompetence, lymphoedema
5. Immunodeficiency
6. Tinea Pedis

Question 3

Investigations for cellulitis

Answer 3

1. WCC, CRP, ESR - raised
2. Wound and blood culture
3. U/S - rule our occult abscess
4. MRI - if thinking osteomyelitis

Question 4

Treatment for cellulitis

Answer 4

Mild/ Moderate Cellulitis

1. Suspected Staph aureus or Strep pyogenes –> Flucloxacillin 500mg 6 hourly
2. S. pyogenes isolated on sulture –> phenoxymethylpenicillin 500mg. If hypersensitive to penicillin can use cephalexin or clindamycin

Severe Cellulitis

1. S.aureus of S.pyogenes –> Flucloxacillin 2g IV, 6-hourly
2. If hypersensitive to penicillins –> cephazolin, vancomycin, clindamycin