Etiology/Diagnosis

• Group A Beta-Hemolytic Strep (Strep Pyogenes) (see Strep Pyogenes)
  • Epidemiolgoy
    • Most common etiology
    • Usually associated with pharyngitis
  • Physiology
    • Release of Exotoxin A
  • Diagnosis
    • Elevated anti-streptolysin-O (ASO)
    • Elevated DNase B
• Staph Aureus (see Staph Aureus): elaborates erythrotoxin
  • Epidemiology
    • Rare etiology
  • Physiology
    • Release of Pyogenic Exotoxin
  • Diagnosis
    • Normal anti-streptolysin-O (ASO)
    • Normal DNase B

Clinical

• Blanching Erytematous Rash (see Exanthems)
  • Diffuse Erythema (blanching): begins on neck and upper trunk
  • Red Follicular Puncta
  • Linear Antecubital Fossa Petechiae
  • Desquamation of involved skin/palms/soles: occurs 5-20 days after onset of eruption
• Pharyngitis
• “White Strawberry Tongue” (seen early): white coating with red papillae
• “Red Strawberry Tongue” (seen later): red tongue with red papillae
• Palatal Petechiae
• Facial Flush with Circumoral Pallor

References

• Enterotoxin B Is the Predominant Toxin Involved in Staphylococcal Scarlet Fever in Taiwan. Clinical Infectious Diseases 2004;38:1498–502