Acute pharyngitis

Last reviewed: 6 Jan 2023
Last updated: 26 Jan 2023
25 Jan 2023

High rates of group A streptococcus infection in England

In a UK Health Security Agency (UKHSA) report, notifications of scarlet fever and invasive group A streptococcus (iGAS) disease in England are higher than expected for this time of year.

Prompt treatment of children with scarlet fever with antibiotics is recommended to reduce risk of possible complications and limit onward transmission. If there is uncertainty about the diagnosis, obtain a throat swab prior to commencing antibiotics. Children with scarlet fever should stay at home until 24 hours of antibiotic treatment has been received.

The Centers for Disease Control and Prevention (CDC) is looking into an increase in iGAS infections among children in the US.

Scarlet fever:

  • Around 90% of cases occur in children under 10 years

  • Usually a mild illness, but is highly infectious

  • Presents with a generalized, erythematous rash, which feels like sandpaper

  • Often preceded by sore throat (pharyngitis, tonsillitis)

  • Pharyngeal erythema with exudates, palatal petechiae, and a red, swollen (strawberry) tongue are suggestive features.

Invasive group A streptococcal infection:

  • The relatively higher rates of iGAS in children this season may reflect increased rates of a preceding viral infection (including respiratory viruses and chickenpox)

  • Clinicians are advised to maintain a high index of suspicion, as early recognition and prompt initiation of specific and supportive therapy for patients with iGAS infection can be life-saving.

Further information from CDC:

Original source of update



History and exam

Key diagnostic factors

  • child or adolescent age
  • winter or spring season (in bacterial pharyngitis)
  • summer/fall season (in enteroviral pharyngitis)
  • rhinorrhea, nasal congestion, and cough (in viral infection)
  • sore throat
  • pharyngeal exudate
  • cervical adenopathy
  • fever
  • headache
  • nausea, vomiting, and abdominal pain
  • conjunctivitis (in measles)
  • maculopapular rash (in measles)
  • Koplik spots (in measles)
  • scarlatiniform rash (in group A Streptococcus [GAS] pharyngitis)
More key diagnostic factors

Other diagnostic factors

  • sexual activity or abuse (in HIV, gonorrheal, or chlamydial infection)
  • treatment failure of penicillin
  • pharyngeal ulceration (in tularemia)
  • pharyngeal gray membrane (in diphtheria)
Other diagnostic factors

Risk factors

  • nasal colonization with group A Streptococcus (GAS)
  • GAS-infected contact
  • sexual activity or abuse
  • ingestion of nondomestic meats
  • immunocompromised host
  • use of inhaled corticosteroids
  • lack of immunization or vaccine failure
  • irradiation
More risk factors

Diagnostic investigations

1st investigations to order

  • rapid antigen test for group A Streptococcus (GAS)
  • nucleic acid amplification (via polymerase chain reaction) for group A Streptococcus (GAS)
More 1st investigations to order

Investigations to consider

  • culture of throat swab for group A Streptococcus (GAS)
  • culture of throat swab for gonococcus or chlamydia
  • serum monospot for Epstein-Barr virus infection
More investigations to consider

Treatment algorithm


all patients



Jeffrey R. Donowitz, MD


Pediatric Infectious Diseases

Children’s Hospital of Richmond

Virginia Commonwealth University




JRD declares that he has no competing interests.


Dr Jeffrey R. Donowitz would like to gratefully acknowledge Dr William A. Petri, Jr, a previous contributor to this topic.


WAP declares that he has no competing interests.

Peer reviewers

Richard Roberts, MD, JD, FAAFP, FCLM

Professor of Family Medicine

University of Wisconsin School of Medicine and Public Health




RR declares that he has no competing interests.

Remco de Bree, MD, PhD


Head and Neck Surgeon

VU University Medical Center


The Netherlands


RdB declares that he has no competing interests.

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