Definition

Site	Term	Common Agents
Epidermis	Impetigo	SAUR, GAS
Upper Dermis	Erysipelas	GAS, other Streptococci

Epidermis/Dermis/ Subcutaneous	Cellulitis	As below
Hair Follicle	Folliculitis/furuncle/
carbuncle	Staphylococci
Lymph nodes	Lymphangitis	Streptococci

Hair-associated infections:

Risk Factors

Barrier Breakdown:
- PMHx Cellulitis
- Skin disorder (Eczema, scar, incision, trauma)
- Neuropathy (repetitive injury)
- IVDU
Local factors:
- Oedema
- Venous insufficiency
- Obesity
Immuosuppression;
- DHx: Immunosuppressives
- Diabetes
- Renal/Liver disease
- Alcoholism

Causative organisms

Staphylococcus aureus (75%)
Streptococcus (A, C/G) (10%)
Uncommonly:
- Streptococcus pneumoniae
- Haemophilus influenzae
- Gram negative
  - Pseudomonas aeruginosa
  - Vibrio vulnificans
- Anaerobes
Animal Bites:
- As above
- Staphylococcus intermedius (Doggy Staph aureus)
- Capnocytophaga canimorsus
- Pasteurella Multocida