Scarlet fever

Scarlet fever is a rash most commonly associated with bacterial pharyngitis in school age and adolescent children ( Salvatore Pardo , Thomas Perera 2019 )

Caused by Group A beta-hemolytic streptococcus Gram positive cocci that grow in chains Classified by their ability to ○ produce hemolysis on blood agar ♦ alpha-hemolytic - partial hemolysis ♦ beta-hemolytic -complete hemolysis ♦ gamma-hemolytic - no hemolysis ○ by differences in carbohydrate cell wall component ♦ A-H and K-T Sometimes also called scarlatina ( older literature ) Notifiable disease in UK Prevalence-Predominantly childhood disease Children between age 2-8 yrs with peak at 4 yrs Rarely before 2 yrs ( maternal antibodies and lack of sensitization ) Seasonal ( spring and winter months in UK ) Highly contagious Outbreak in overcrowded situations ( eg schools , situational settings ) Transmission - via aerosol droplets and direct contact Incubation period 2-3 days ( but can range from 1-6 days )

pathophysiology-Toxin mediated disease Exotoxins from strains of Streptococcus pyogens also known as Group A Streptococcus (GAS ) Local production of inflammatory mediators and alteration of the cutaneous cytokine milieu○ inflammatory response and dilatation of blood vessels --> scarlet color of rash GAS- can be normal commensal...