Acute pharyngitis

Definition and clinical purpose

Acute pharyngitis is acute inflammation of the tonsils and pharynx. Most cases are viral, self-limited, and do not need antibiotics.

Group A streptococcus is the main bacterial cause, especially in children 3 to 14 years. The clinical task is to identify patients who need antibiotics because appropriate treatment prevents acute rheumatic fever and reduces selected suppurative complications.

Do not treat every red or exudative throat as bacterial disease; viral and streptococcal pharyngitis can look similar.

Clinical features

• Common findings include throat pain, painful swallowing, inflamed tonsils and pharynx, tender anterior cervical lymph nodes, and fever that may or may not be present.
• Erythematous or exudative pharyngitis can be viral or group A streptococcal; use the clinical pattern, risk factors, rapid test if available, and local epidemiology.
• In adolescents and young adults, marked fatigue with generalised lymph node enlargement and possible splenomegaly suggests Epstein-Barr virus infectious mononucleosis.
• Erythematous or exudative pharyngitis can also occur with gonococcal infection or primary HIV; sexual exposure and systemic features guide testing and treatment.
• Vesicles or small ulcers on the tonsils are usually viral, commonly coxsackie virus or primary herpes infection.
• A painless hard tonsillar ulcer suggests syphilis; a soft ulcer with poor oral hygiene and foul breath suggests Vincent tonsillitis.
• Koplik spots with conjunctivitis and rash suggest measles. A red bumpy tongue with rash suggests scarlet fever due to group A streptococcus.

Centor assessment

Where rapid testing is not available, Centor criteria can reduce unnecessary empirical antibiotics. A score below 2 makes group A streptococcal pharyngitis unlikely.

Do not rely on Centor scoring alone in patients with immunosuppression, personal or family history of acute rheumatic fever, or high risk for local or systemic complications; these patients need clinician-directed antibiotic decisions.

Complications and differential diagnosis

• Local complications include peritonsillar, retropharyngeal, and lateral pharyngeal abscess. Warning signs are fever, intense unilateral pain, severe dysphagia, hoarse or muffled voice, trismus, and uvula deviation.
• Systemic toxin disease suggests diphtheria. Post-streptococcal complications include acute rheumatic fever and acute glomerulonephritis.
• Children with severe dehydration, severe swallowing difficulty, upper-airway compromise, or deteriorating general condition need hospital assessment.
• Epiglottitis is an important differential diagnosis when there is drooling, tripod position, respiratory distress, stridor, toxic appearance, or absence of the typical viral cough pattern.
• Pseudomembranous pharyngitis requires the diphtheria pathway. Gonococcal and syphilitic pharyngitis require STI evaluation and treatment.

Symptomatic treatment

• Treat fever and throat pain with paracetamol or ibuprofen when not contraindicated.
• Encourage oral fluids and feeding as tolerated. Assess dehydration when swallowing is limited.
• Give return advice for breathing difficulty, drooling, inability to swallow, worsening fever, rash, neck swelling, one-sided severe pain, trismus, reduced urine, or failure to improve.

Antibiotic treatment for likely GAS

Use antibiotics for Centor score 2 or more, scarlet fever, positive rapid test, or high-risk patients according to local protocol. Single-dose benzathine benzylpenicillin is preferred where safe injection practice is available because adherence is assured and penicillin resistance in group A streptococcus remains rare.

• Treat gonococcal or syphilitic pharyngitis using the STI protocols. Treat diphtherial pharyngitis using the diphtheria pathway.
• Vincent tonsillitis can be treated with metronidazole or amoxicillin according to local protocol.
• Peritonsillar, retropharyngeal, or lateral pharyngeal abscess requires referral for surgical drainage.
• Hospitalise children with serious illness or features of epiglottitis.

Prevention and follow-up

• Prevention includes hand hygiene, respiratory etiquette, reduced crowding where feasible, vaccination against measles and diphtheria, and timely treatment of confirmed or likely group A streptococcal disease in high-risk settings.
• Review if symptoms worsen, fever persists, the patient cannot drink, rash develops, neck swelling appears, or there is no expected improvement after symptomatic care or after 48 hours of appropriate antibiotics.
• Handover should include age, duration, Centor features, rapid test result if done, allergy history, acute rheumatic fever risk, airway signs, abscess signs, rash, suspected STI or diphtheria features, medicines given, and follow-up plan.