Acute Sore Throat and Scarlet Fever

Important: Notes

• If  trismus, stridor or breathing difficulties are present, arrange for urgent hospital transfer and do not examine the throat as this can cause acute airway obstruction in epiglottitis.
• Pharyngitis is usually a viral infection (50-80%). Streptococcal infection is most likely in children from 5 to 15 years and less likely in younger or older patients. In >90% of cases, resolution of symptoms occurs within 7 days without any antibiotic treatment. 
• Group A Streptococci are universally penicillin susceptible.
• Use the FeverPAIN Score to assess need for antimicrobial prescription (1 point each):
  • Fever in last 24h
  • Purulent tonsillar exudate
  • Attending after duration of symptoms <3 days
  • Severely Inflamed tonsils
  • No cough or coryza

• Do not take throat swabs routinely, even if the sore throat persists.  Throat swabs have poor specificity and sensitivity.

• Scarlet fever is a notifiable infectious disease caused by toxin producing strains of Group A streptococcus (S. pyogenes). Group A Streptococci are universally penicillin susceptible. Notification to the Health Protection Team should be made based on clinical suspicion.
• The primary site of infection is usually the throat and the initial symptoms of Scarlet fever are those of streptococcal pharyngitis. A faint red rash, which feels like sand-paper, develops after 12-48hrs. Sparing of the area around the mouth is typical. As the rash fades, the skin of the fingertips, toes and groin peels off. The tongue first shows a white coating, then peels a few days later and looks red and swollen ('strawberry tongue').
• Consider admission for any patient with valvular disease or significant immunocompromise or if you suspect a complication of streptococcal infection such as acute rheumatic fever or a deep neck space infection. 'Septic' or 'toxic' scarlet fever is associated with invasive Group A streptococcal disease. Patients develop a high fever and marked systemic toxicity, and may have symptoms such as diarrhoea and vomiting, arthralgia and jaundice. This is a medical emergency with a high mortality that should be admitted immediately.
• Scarlet fever is a clinical diagnosis and throat swabs to identify S. pyogenes may not be helpful, due to poor specificity and sensitivity.
• Advise the patient to stay away from school or work for at least 1 day after starting antibiotic treatment, wash their hands frequently, avoid sharing eating utensils and towels, dispose of handkerchiefs promptly, and avoid contact with anyone at particular risk of infection (e.g. people with valvular disease or who are immunocompromised). Advise to return for follow up if symptoms have not improved or have worsened after 7 days.