Clinical management and impact of scarlet fever in the modern era: findings from a cross-sectional study of cases in London, 2018-2019.

Abstract Background Scarlet fever incidence has risen steeply in recent years, and is associated with wider outbreaks of severe Group A Streptococcal infections. Yet, few studies of its epidemiology, clinical features, and management have been undertaken in the antibiotic era. Aim To characterize symptomatology, management, and consequences of scarlet fever and identify associations with delayed diagnosis. Design/Setting Cross-sectional study of children with scarlet fever in London, 2018-2019. Methods online survey of parents/guardians of children with scarlet fever identified by Health Protection Teams, recording demographics, symptoms, care-seeking, and management; logistic regression for factors associated with delayed diagnosis; Cox’s regression for consequences of delayed diagnosis. Results Responses represented 412 cases in a period with 6828 notifications for children 0-14 years old, and 410 school/nursery outbreaks. 70% first sought care from general practice, and 31% had multiple consultations. For 28%, scarlet fever was not considered at first consultation: in these cases, symptoms were frequently attributed to viral infection (60%, 64/106). Delay in diagnosis beyond first consultation occurred more frequently among children aged 5+ who presented with sore throat (odds ratio 2.8 vs. 5+ without sore throat; 95%CI 1.3-5.8; P=0.006). On average, cases with delayed diagnosis took one day longer to return to baseline activities, and required one additional day off school versus those diagnosed at first consultation. Conclusions In assessing children with fever, rash, and sore throat, practitioners should be alert to the possibility of scarlet fever: it is frequently missed at first consultation, and prompt recognition speeds clinical recovery and public health management. How this fits in [4 sentences summarising key messages of background and findings] -In the five years leading up to the pandemic lockdown of 2020, scarlet fever incidence rose markedly in England and Wales, prompting this investigation of cases in London 2018-2019. -Prompt recognition of the disease by carers and clinicians can direct timely antibiotic therapy, limit transmission in the household and community, and direct the identification and control of outbreaks. -In this study, delayed diagnosis was more likely to occur among older children presenting with sore throat—perhaps reflecting a lower index of suspicion in this age group. -Cases with delayed diagnosis took longer to return to normal activities, and required more time off from school than those diagnosed at the first consultation.