Pharyngitis is an inflammation and commonly an infection of the pharynx and its lymphoid tissues. Viral causes account for 90% of all cases. Group A β-hemolytic streptococci (GABHS) are responsible for up to 50% of bacterial infections. Other bacterial causes include other streptococci, M pneumoniae, Neisseria gonorrhoeae, and Corynebacterium diphtheriae. In immunocompromised patients and patients on antibiotics, Candida species can cause thrush.
Patients with bacterial pharyngitis present with an acute onset of sore throat and fever, frequently accompanied by nausea, vomiting, headache, and abdominal cramping. They may have an erythematous posterior pharynx and palatine tonsils, tender cervical lymphadenopathy, and palatal petechiae. Classically, the tonsils have a white or yellow exudate with debris in the crypts; however, many patients do not have exudate on examination. Viral pharyngitis is typically more benign, with a gradual onset, less fever, and less impressive erythema and swelling of the pharynx. Infectious mononucleosis can take weeks to resolve, whereas most cases of viral pharyngitis are self-limited, with spontaneous resolution in a matter of days. Lingual and adenoid tonsillitis may also be present.
Management and Disposition
Treatment is largely supportive except for antibiotics and rehydration. Analgesics, antipyretics, and throat sprays or gargles can provide symptomatic relief. Patients with known or suspected GABHS require antibiotics primarily to prevent rheumatic fever and suppurative complications. Centor criteria clinical decision rules developed to guide physicians in testing and prescribing of antibiotics include: (1) tonsillar exudates, (2) tender anterior cervical adenopathy, (3) fever by history, and (4) absence of cough. Neither antibiotic treatment nor diagnostic testing is recommended with fewer than two criteria. Most authorities now favor evaluation using a sensitive rapid streptococcal antigen test (RSAT) for GABHS, without throat culture for negative results in adult patients with two or more Centor criteria. In children, it is recommended that all negative RSAT be followed up with a throat culture. Current first-line antibiotic therapies remain a single dose of intramuscular benzathine penicillin or oral penicillin for 10 days.
Palatal Petechiae. Palatal petechiae and erythema of the tonsillar pillars in a patient with streptococcal pharyngitis. (Photo contributor: Kevin J. Knoop, MD, MS.)
Streptococcal Pharyngitis–Palatal Petechiae. Test-proven streptococcal pharyngitis in a patient with fever, sore throat, and cervical adenopathy. (Photo contributor: Lawrence B. Stack, MD.)
Exudative Pharyngitis. Intense erythema with scant exudates is seen in this early (< 24 hours) case of GABHS pharyngitis. (Photo contributor: Kevin J. Knoop, MD, MS.)
Tonsillar Exudate. White and yellow cryptic exudates are seen in this patient with rapid strep test proven streptococcal pharyngitis. (Photo contributor: Lawrence B. Stack, MD.)