scarlet fever

Last reviewed 06/2022

Scarlet fever results from an infection with Streptococcus pyogenes or group A beta haemolytic streptococci that produces an erythrogenic toxin (1,2).

Group A beta haemolytic streptococci is commonly found on the skin or in the throat and is responsible for causing bacterial sore throat or “strep throat” (1,2). It may also cause:

  • impetigo
  • bacteraemia
  • necrotizing fasciitis
  • streptococcal toxic shock syndrome (2).

Scarlet fever is primarily a childhood disease and is commonly seen in children between the ages of two and eight years (1).

It is a highly contagious infection. Transmission occurs when bacteria (present in an infected person’s saliva or mucous)

  • is spread by aerosol - sneezing, coughing, or breathing out
  • comes into direct contact with an uninfected person (1)

Although scarlet fever is seen after streptococcal sore throat in a majority of the patients, it may also occur following burns or an infected wound (2).

Invasive group A streptococcal disease and scarlet fever are notifiable disease under the Health Protection (Notification) Regulations 2010 (3).

This disease has an incubation period of two to four days (2).

A milder form of scarlet fever is described by some clinicians as “scarlatina” although others consider this to be a synonym for scarlet fever (2)

Click here for an example image of scarlet fever rash