Common Causes of Throat Pain in Relatively Healthy Adults
Most throat pain in healthy adults is caused by viral infections, with rhinovirus, coronavirus, adenovirus, influenza, parainfluenza, and enterovirus being the most common culprits, while Group A Streptococcus accounts for only 5-15% of cases and is the primary bacterial pathogen requiring treatment. 1, 2
Viral Causes (Most Common)
Viral pathogens cause the vast majority of pharyngitis cases and include: 1, 2
- Respiratory viruses: Rhinovirus, coronavirus, adenovirus, respiratory syncytial virus, influenza, and parainfluenza are the most frequent causes 1, 2
- Herpes viruses: Herpes simplex virus, Epstein-Barr virus (infectious mononucleosis), and cytomegalovirus 1, 2
- Enteroviruses: Coxsackievirus and echoviruses, which may cause characteristic vesicles (herpangina) 1, 2
Clinical Features Suggesting Viral Etiology
Patients with viral pharyngitis typically present with: 1, 2
- Cough (most important distinguishing feature) 1
- Nasal congestion or rhinorrhea 1, 2
- Conjunctivitis 1, 2
- Hoarseness 1
- Diarrhea 1, 2
- Oropharyngeal ulcers or vesicles 1, 2
Bacterial Causes (Less Common)
Group A Streptococcus (Primary Bacterial Pathogen)
Group A Streptococcus is the predominant bacterial cause, accounting for only 5-15% of adult pharyngitis cases, but is the only common cause requiring antibiotic treatment. 1, 3, 4
Clinical features suggesting streptococcal infection include: 1
- Sudden-onset severe sore throat 1
- Persistent fever (101-104°F) 1
- Tonsillar exudates 1
- Tender anterior cervical lymphadenopathy 1
- Absence of cough (critical distinguishing feature) 1
- Palatal petechiae 1
- Scarlatiniform rash 1
Other Bacterial Causes (Rare)
- Fusobacterium necrophorum: Implicated in 10-20% of endemic pharyngitis in adolescents and young adults, can lead to life-threatening Lemierre syndrome 1
- Groups C and G streptococci 1
- Neisseria gonorrhoeae: Consider in sexually active patients with appropriate risk factors 1, 5
- Mycoplasma pneumoniae and Chlamydia pneumoniae: May present with associated atypical pneumonia 1, 5
- Arcanobacterium hemolyticum: Can cause scarlatiniform rash 1
Serious/Life-Threatening Causes Requiring Urgent Evaluation
Patients with unusually severe signs warrant immediate evaluation for deep space infections: 1, 6
- Peritonsillar abscess: Presents with severe odynophagia, muffled voice, drooling, tonsillar asymmetry, and trismus 1, 6
- Parapharyngeal abscess: Neck tenderness or swelling 1, 6
- Epiglottitis: Difficulty swallowing with drooling suggesting airway compromise 1, 6
- Lemierre syndrome: Severe pharyngitis in adolescents/young adults with neck tenderness or swelling 1, 6
Non-Infectious Causes (Uncommon)
- Thyroiditis 5
- Candidal infection: Should prompt consideration of HIV infection in appropriate clinical context 5
- Post-surgical or post-radiation changes 7
Critical Clinical Pitfall
Over 60% of adults with sore throat receive antibiotic prescriptions despite most cases being viral and self-limited. 1, 8 The Modified Centor criteria should be used to identify patients requiring testing: fever by history, tonsillar exudates, tender anterior cervical adenopathy, and absence of cough. 1 Patients with fewer than 2 criteria do not need testing or antibiotics. 3