Pharyngitis is one of the most common outpatient presentations — and one of the most commonly overtreated. The primary reason to treat Group A Streptococcus is not symptom relief. It is prevention of acute rheumatic fever. That goal requires a full 10-day course. Treating viral pharyngitis with antibiotics provides no benefit and drives resistance.
CLINICAL PRINTABLE
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A one-page Pharyngitis clinical reference is on the way.
1 · Recognition
- Viral pharyngitis: gradual onset, associated with rhinorrhea, cough, hoarseness, oral ulcers, or conjunctivitis. Caused by rhinovirus, adenovirus, EBV, CMV, HSV, influenza. Cough and rhinorrhea strongly suggest viral etiology.
- Streptococcal pharyngitis (GAS): sudden onset sore throat, fever, tonsillar exudate, anterior cervical lymphadenopathy, absence of cough. Centor criteria: each of these four features adds 1 point.
- Modified Centor (McIsaac) criteria: Centor criteria plus age adjustment (add 1 point for age 3–14, subtract 1 point for age ≥45). Score 0–1: no testing or antibiotics. Score 2–3: rapid antigen test (RADT). Score ≥4: treat empirically or test.
- Infectious mononucleosis (EBV): severe pharyngitis with exudate, posterior cervical lymphadenopathy, splenomegaly, fatigue, and atypical lymphocytes on CBC. Monospot test (heterophile antibody) or EBV-specific antibodies. Avoid aminopenicillins when EBV is suspected — an associated rash can occur; the reported frequency varies and is lower than historical estimates in contemporary studies.
- Peritonsillar abscess: unilateral tonsillar swelling, uvular deviation toward the contralateral side, muffled 'hot potato' voice, trismus, drooling. Requires needle aspiration or incision and drainage plus antibiotics. ENT referral.
2 · Differential / Mimics
Infectious mononucleosis
Severe pharyngitis, posterior cervical lymphadenopathy, splenomegaly, fatigue. Monospot positive. Avoid amoxicillin/ampicillin. Activity restriction if splenomegaly present (risk of splenic rupture).
Peritonsillar abscess
Unilateral swelling, uvular deviation, trismus, muffled voice. Requires drainage plus antibiotics. ENT referral for drainage if not comfortable with needle aspiration.
Epiglottitis
Severe sore throat, dysphagia, drooling, muffled voice, stridor. Tripod positioning. Airway emergency — do not examine the throat with a tongue depressor. Immediate airway management and ENT/anesthesia.
Gonococcal pharyngitis
Sexually transmitted. Often asymptomatic or mild. Consider in sexually active patients with pharyngitis and risk factors. NAAT for diagnosis. Treat with ceftriaxone.
3 · Treatment Pathway
Viral pharyngitis — symptomatic management
Analgesics (NSAIDs or acetaminophen), throat lozenges, warm saltwater gargles. Antibiotics are not indicated. Symptoms resolve within 3–7 days.
GAS pharyngitis — antibiotic treatment
Penicillin V 500 mg twice daily for 10 days, or amoxicillin 500 mg twice daily for 10 days (preferred for palatability). Benzathine penicillin G IM single dose for adherence concerns. Azithromycin or clindamycin for penicillin allergy.
Goals of GAS treatment
Prevent acute rheumatic fever (ARF) — the primary indication for antibiotic treatment. Reduce symptom duration by 1–2 days. Reduce transmission. Prevent suppurative complications (peritonsillar abscess, otitis media, sinusitis).
Testing strategy
Rapid antigen detection test (RADT): high specificity (~99%), moderate sensitivity (~70–90%). Negative RADT in children should be confirmed with throat culture. Negative RADT in adults does not require culture confirmation (lower GAS prevalence). Do not test or treat patients with clear viral features (cough, rhinorrhea, oral ulcers).
Recurrent GAS pharyngitis
Distinguish true recurrence from carrier state. GAS carriers have positive throat culture but are not at risk for ARF and do not require treatment. Tonsillectomy for recurrent GAS pharyngitis meeting criteria (≥7 episodes/year, ≥5/year for 2 years, ≥3/year for 3 years).
4 · Expected Response
- Viral pharyngitis: symptoms resolve within 3–7 days without treatment. Fever typically resolves within 2–3 days.
- GAS pharyngitis with antibiotics: fever resolves within 24–48 hours. Throat pain improves within 2–3 days. Patients are no longer contagious after 24 hours of antibiotics.
- Failure to improve within 48–72 hours of antibiotics: reconsider diagnosis (EBV, peritonsillar abscess, resistant organism), obtain throat culture, and reassess.
5 · Escalation
- Peritonsillar abscess: ENT referral for needle aspiration or incision and drainage. IV antibiotics (ampicillin-sulbactam or clindamycin). Hospitalization for severe cases or airway compromise.
- Epiglottitis: airway emergency. Do not examine the oropharynx with a tongue depressor. Immediate ENT and anesthesia involvement. Lateral neck X-ray ('thumbprint sign') if patient is stable. IV antibiotics (ceftriaxone).
- Retropharyngeal or parapharyngeal abscess: neck stiffness, dysphagia, drooling, neck swelling. CT neck with contrast. ENT and surgical consultation.
- Lemierre syndrome: septic thrombophlebitis of the internal jugular vein following pharyngitis. Fusobacterium necrophorum. Septic emboli to lungs. CT neck and chest. IV antibiotics (beta-lactam/beta-lactamase inhibitor or metronidazole).
Apply It · Change One Detail
APPLY IT
A 19-year-old presents with 2 days of severe sore throat, fever of 38.9°C, tonsillar exudate, and tender anterior cervical lymphadenopathy. No cough or rhinorrhea. McIsaac score is 4 (fever, exudate, anterior lymphadenopathy, age 3–14 equivalent — but this patient is 19, so score is 3). RADT is positive. Treat with amoxicillin 500 mg twice daily for 10 days. Counsel that they are no longer contagious after 24 hours of antibiotics.
CHANGE ONE DETAIL
Change one detail — the same patient has a sore throat but also has rhinorrhea, cough, and oral ulcers. McIsaac score is 0. This is viral pharyngitis. RADT is not indicated. Symptomatic management with NSAIDs and throat lozenges. Antibiotics will not help and may cause harm.
Bottom Line
Cough and rhinorrhea strongly suggest viral pharyngitis — do not test or treat with antibiotics when viral features are present. The primary reason to treat GAS is prevention of acute rheumatic fever.
EVIDENCE & REFERENCES
- Shulman ST, et al. Clinical practice guideline for the diagnosis and management of group A streptococcal pharyngitis: 2012 update by the IDSA. Clin Infect Dis. 2012;55(10):e86-102. doi:10.1093/cid/cis629
- Choby BA. Diagnosis and treatment of streptococcal pharyngitis. Am Fam Physician. 2009;79(5):383-390.