scarlet fever (2nd disease)

Etiology

Group A Streptococcus

Epidemiology

• most common in children 2-10 years of age
• generally follows group A Streptococcal pharyngitis
• increase in scarlet fever in England 2014-2016
• a new emm1 strain (M1UK) of Streptococcus pyogenes associated with outbreak of scarlet fever in 2014-2016 in the UK produces 9X more streptococcal pyrogenic exotoxin A than other emm1 strains

Pathology

• streptococcal pyrogenic exotoxin A
• streptococcal pyrogenic exotoxin B
• streptococcal pyrogenic exotoxin C

Clinical manifestations

• diffuse, blanchable erythema beginning on face, spreading to trunk & extremities
• circumoral pallor
• sandpaper texture to skin
• accentuation of linear erythema in skin folds (Pastia's lines)
• exanthem of white tongue evolving into red 'strawberry' tongue
• desquamation in 2nd week
• fever
• pharyngitis
• headache

Laboratory

• rapid screen for group A Streptococcus

Management

• see Group A beta-hemolytic Streptococcus

More general terms

• Streptococcal infection; streptococcosis
• childhood exanthem (numbered diseases)

Additional terms

• Dukes disease (4th disease)
• erythema infectiosum (5th disease)
• measles (1st disease)
• roseola (exanthem subitum, 6th disease)
• rubella (German measles, 3rd disease)