Following a prolonged decline in the prevalence of scarlet fever since the late 19th century, outbreaks have re-emerged from around 2011 in mainland China, Hong Kong, South Korea, Taiwan, Singapore, and Vietnam, and from around 2014 in the UK and other European countries.[8]Hurst JR, Brouwer S, Walker MJ, et al. Streptococcal superantigens and the return of scarlet fever. PLoS Pathog. 2021 Dec;17(12):e1010097.
https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1010097
http://www.ncbi.nlm.nih.gov/pubmed/34969060?tool=bestpractice.com
[9]Walker MJ, Brouwer S. Scarlet fever makes a comeback. Lancet Infect Dis. 2018 Feb;18(2):128-9.
http://www.ncbi.nlm.nih.gov/pubmed/29191627?tool=bestpractice.com
In England, the incidence of scarlet fever tripled in 2014 compared with 2013.[5]Lamagni T, Guy R, Chand M, et al. Resurgence of scarlet fever in England, 2014-16: a population-based surveillance study. Lancet Infect Dis. 2018 Feb;18(2):180-7.
https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(17)30693-X/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/29191628?tool=bestpractice.com
The median age of cases in 2014 was 4 years old and outbreaks were common in nurseries and schools. Over 19,000 cases were reported in England in 2016.[5]Lamagni T, Guy R, Chand M, et al. Resurgence of scarlet fever in England, 2014-16: a population-based surveillance study. Lancet Infect Dis. 2018 Feb;18(2):180-7.
https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(17)30693-X/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/29191628?tool=bestpractice.com
These outbreaks have been associated with low mortality, unlike in previously documented epidemics in the 19th and early 20th centuries.[9]Walker MJ, Brouwer S. Scarlet fever makes a comeback. Lancet Infect Dis. 2018 Feb;18(2):128-9.
http://www.ncbi.nlm.nih.gov/pubmed/29191627?tool=bestpractice.com
However, it is unclear whether this difference in outcome is due to Streptococcus pyogenes (group A streptococcus [GAS]) strain variation, modern diagnosis and patient care, better sanitation, widespread use of antibiotics, or other factors.[9]Walker MJ, Brouwer S. Scarlet fever makes a comeback. Lancet Infect Dis. 2018 Feb;18(2):128-9.
http://www.ncbi.nlm.nih.gov/pubmed/29191627?tool=bestpractice.com
Although the mortality rate is low, a resurgence in scarlet fever outbreaks has resulted in increased hospital admissions.[5]Lamagni T, Guy R, Chand M, et al. Resurgence of scarlet fever in England, 2014-16: a population-based surveillance study. Lancet Infect Dis. 2018 Feb;18(2):180-7.
https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(17)30693-X/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/29191628?tool=bestpractice.com
[9]Walker MJ, Brouwer S. Scarlet fever makes a comeback. Lancet Infect Dis. 2018 Feb;18(2):128-9.
http://www.ncbi.nlm.nih.gov/pubmed/29191627?tool=bestpractice.com
Scarlet fever can occur at any age but mainly affects children ages 1-10 years, and it is most common in children ages 3-6 years. Scarlet fever is uncommon in children <1 year old and in adults.[5]Lamagni T, Guy R, Chand M, et al. Resurgence of scarlet fever in England, 2014-16: a population-based surveillance study. Lancet Infect Dis. 2018 Feb;18(2):180-7.
https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(17)30693-X/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/29191628?tool=bestpractice.com
[6]Liu Y, Chan TC, Yap LW, et al. Resurgence of scarlet fever in China: a 13-year population-based surveillance study. Lancet Infect Dis. 2018 Aug;18(8):903-12.
https://www.thelancet.com/journals/laninf/article/PIIS1473-3099(18)30231-7/fulltext
http://www.ncbi.nlm.nih.gov/pubmed/29858148?tool=bestpractice.com
[7]Staszewska-Jakubik E, Czarkowski MP, Kondej B. Scarlet fever in Poland in 2014. Przegl Epidemiol. 2016;70(2):195-202.
http://www.ncbi.nlm.nih.gov/pubmed/27779834?tool=bestpractice.com
GAS infection is responsible for about 15% to 30% of pharyngitis episodes in children, and for around 5% to 15% of pharyngitis infections in adults.[2]Shulman ST, Bisno AL, Clegg HW, et al. Clinical practice guideline for the diagnosis and management of group A streptococcal pharyngitis: 2012 update by the Infectious Diseases Society of America. Clin Infect Dis. 2012 Nov 15;55(10):e86-102. [Erratum in: Clin Infect Dis. 2014 May;58(10):1496.]
https://academic.oup.com/cid/article/55/10/e86/321183
http://www.ncbi.nlm.nih.gov/pubmed/22965026?tool=bestpractice.com
It is estimated that scarlet fever develops in about 10% of patients with GAS pharyngitis.