A Synopsis of AFP's "Diagnosis and Treatment of Streptococcal Pharyngitis"

Diagnosis and Treatment of Streptococcal Pharyngitis
BETH A. CHOBY, MD, University of Tennessee College of Medicine–Chattanooga, Chattanooga, Tennessee
Am Fam Physician. 2009 Mar 1;79(5):383-390.
http://www.aafp.org/afp/2009/0301/p383.pdf

     The most common bacterial pharyngitis is Group A beta-hemolytic streptococcus (GAS). It peaks in the late winter and early spring.  Differentiating bacterial from viral using history and physical is not effective. GAS infection is suggested if the patient has a sore throat, acute fever, and recent GAS exposure. Cervical lymph nodes, pharyngeal or tonsillar inflammation/exudates are also common.  Cough, coryza, conjunctivitis and diarrhea are more likely due to viral illness.
     The Modified Centor score is used to determine whether antibiotics are appropriate. One point is given for each of the criteria listed below:

Absence of cough +1
Swollen and tender anterior cervical nodes +1
T' >100.4'F +1
Tonsillar exudates/ swelling +1
Age 3-14 yrs old +1
Age 15-44 yrs old +0
Age 45 years and older -1

Patients with a score of one or less do not need antibiotics. Patients with a score of 4 or more should be treated empirically with antibiotics. Those with a score of 2-3 should have a throat culture or RADT. Positive results should trigger treatment with antibiotics. 
     GAS pharyngitis will usually resolve without treatment, but treatment may prevent systemic and community spread. Acute rheumatic fever is a very rare complication. Lemierre syndrome (an internal jugular vein thrombosis) can be caused by untreated  non-GAS pharyngitis, Fusobacterium necrophorum.
     First line treatment includes penicillin, amoxicillin, ampicillin, or clindamycin. Erythromycin can be used in patients with a "TRUE" penicillin allergy. If erythromycin causes GI issues, azithromycin or clarithromycin can be used. The data on tonsillectomy effectiveness is limited.