Description

• Superficial bacterial infection of the skin with prominent lymphatic involvement
• Leukocytosis is common
• Positive blood cultures in 3–5%
• Involves the upper dermis including the superficial lymphatics
• In contrast, cellulitis affects the deeper dermis and subcutaneous fat

Etiology

• Group A β-hemolytic streptococcus is the causative organism (less commonly, group C or G streptococci)
• Portals of entry:
  • Skin ulcers
  • Local trauma
  • Abrasions
  • Psoriatic or eczematous lesions
  • Fungal infections

• Haemophilus influenzae type b (HIB) causes facial cellulitis in children that may appear similar to erysipelas:
  • Should be considered in unimmunized children
  • Many will be bacteremic and require admission
  • Cefuroxime or other appropriate H. influenzae coverage is important
  • H. influenzae is much less common since widespread use of the HIB vaccine
• Group B streptococci can cause erysipelas in the newborn
• Can develop from infection of umbilical stump

• Erythema of the breast in puerperal mastitis is often caused by Staphylococcus organisms, hence methicillin-resistant S. aureus (MRSA) should be covered
  • See Mastitis