Scarlet fever: A not so typical exanthematous pharyngotonsillitis (based on 171 cases)

Area of Science:

• Pediatrics
• Infectious Diseases
• Microbiology

Background:

• Scarlet fever, a bacterial illness caused by Streptococcus pyogenes, typically presents with pharyngitis and a characteristic rash.
• Differentiating scarlet fever from streptococcal pharyngotonsillitis is crucial for appropriate treatment and management.
• Current clinical prediction rules may not accurately reflect the presentation of scarlet fever in contemporary pediatric populations.

Purpose of the Study:

• To characterize the current age distribution, clinical signs, and symptoms of pediatric scarlet fever.
• To compare the clinical presentation of scarlet fever with traditional streptococcal pharyngotonsillitis.

Main Methods:

• An observational, retrospective study analyzed clinical records of 5500 children (0-15 years).
• Data collected included the prevalence of signs and symptoms and the Centor score.
• Microbiological confirmation was performed using rapid antigen-detection tests or traditional culture.

Main Results:

• Of 252 scarlet fever diagnoses, 171 were microbiologically verified in 158 patients, with a median age of 3.8 years (57% under 4 years).
• Common symptoms included fever (89%), high fever >38°C (73%), enlarged lymph nodes (70%), and absence of cough (73%).
• Tonsillar exudate was infrequent (24%), and the Centor score was ≤2 in 86% of cases. Younger children (<4 years) had significantly higher fevers.

Conclusions:

• Pediatric scarlet fever pharyngotonsillitis exhibits distinct clinical features compared to traditional streptococcal pharyngotonsillitis.
• Clinical prediction rules like Centor or McIsaac may be questionable for diagnosing scarlet fever.
• The presence of a rash is identified as the primary diagnostic clue, irrespective of patient age.