What is the appropriate workup and treatment for acute pharyngitis (sore throat)?

From the Guidelines

For a sore throat workup and treatment, first determine if the cause is viral or bacterial, and for confirmed strep throat, prescribe amoxicillin 500mg three times daily for 10 days (or penicillin V 500mg twice daily for 10 days) as the first line of treatment, as recommended by the Infectious Diseases Society of America 1. For symptomatic relief of any sore throat, recommend acetaminophen 650mg every 6 hours or ibuprofen 400-600mg every 6-8 hours, warm salt water gargles (1/4 teaspoon salt in 8oz warm water), throat lozenges, and adequate hydration. Some key points to consider in the workup and treatment of acute pharyngitis include:

• Most sore throats (80-90%) are viral and will resolve on their own within 7-10 days
• If bacterial pharyngitis (strep throat) is suspected based on fever, tonsillar exudates, tender anterior cervical lymphadenopathy, and absence of cough, perform a rapid strep test or throat culture
• For penicillin-allergic patients, use azithromycin 500mg on day 1, then 250mg daily for days 2-5, or clindamycin 300mg three times daily for 10 days, as alternative treatment options 1
• Adjunctive therapy with analgesic/antipyretic agents such as acetaminophen or NSAIDs may be useful in managing moderate to severe symptoms or controlling high fever associated with GAS pharyngitis 1 Treatment prevents complications like rheumatic fever and reduces symptom duration. If symptoms persist beyond 10 days, worsen after initial improvement, or include difficulty breathing or swallowing, further evaluation is needed to rule out peritonsillar abscess or other complications.

From the FDA Drug Label

In three double-blind controlled studies, conducted in the United States, azithromycin (12 mg/kg once a day for 5 days) was compared to penicillin V (250 mg three times a day for 10 days) in the treatment of pharyngitis due to documented Group A β-hemolytic streptococci (GABHS or S. pyogenes) Azithromycin was clinically and microbiologically statistically superior to penicillin at Day 14 and Day 30 with the following clinical success (i.e., cure and improvement) and bacteriologic efficacy rates (for the combined evaluable patient with documented GABHS): Three U. S. Streptococcal Pharyngitis Studies Azithromycin vs. Penicillin V EFFICACY RESULTS Day 14Day 30 Bacteriologic Eradication: Azithromycin323/340 (95%)255/330 (77%) Penicillin V242/332 (73%)206/325 (63%) Clinical Success (Cure plus improvement): Azithromycin336/343 (98%)310/330 (94%) Penicillin V284/338 (84%)241/325 (74%)

The appropriate treatment for acute pharyngitis (sore throat) caused by Group A β-hemolytic streptococci (GABHS) is azithromycin (12 mg/kg once a day for 5 days) or penicillin V (250 mg three times a day for 10 days).

• Workup is not explicitly mentioned in the label, but it can be inferred that a diagnosis of GABHS should be documented before initiating treatment.
• The clinical success rate for azithromycin was 98% at Day 14 and 94% at Day 30.
• The most common side effects were diarrhea/loose stools, vomiting, and abdominal pain. 2

From the Research

Diagnosis of Acute Pharyngitis

• A thorough history and physical examination are essential for the appropriate selection of diagnostic tests for sore throat 3
• Routine testing for the uncomplicated case should consist of a pharyngeal culture in most patients, with rapid streptococcal antigen testing only for the more severe cases 3
• A directed history and physical examination, looking for exudative pharyngitis with fever, adenopathy and lack of cough or other respiratory symptoms, can help identify patients with group A beta-hemolytic streptococcal (GABHS) pharyngitis 4

Treatment of Acute Pharyngitis

• Those with positive streptococcal tests should be treated to prevent rheumatic fever and mitigate symptoms in severe cases 3
• Sore throat caused by viruses usually resolves spontaneously 3
• Antibiotics can reduce the duration of symptoms by about 16 hours overall, and reduce the likelihood of headache and some sore throat complications 5, 6
• The use of antibiotics should be judged on an individual basis, considering the potential benefits and harms, including the risk of antimicrobial resistance 5
• Symptomatic treatment with systemic analgesics such as acetylsalicylic acid, acetaminophen, flurbiprofen, or ibuprofen is a valid option 7
• Local anesthetics such as lidocain, benzocaine, and ambroxol can be recommended in the first-line treatment of acute sore throat 7

Prevention of Complications

• Antibiotics can reduce the incidence of acute otitis media, quinsy, and acute rheumatic fever 5, 6
• The trend is that antibiotics may protect against acute glomerulonephritis, but there are too few cases to be sure 5, 6
• The number needed to treat to benefit (NNTB) to prevent one sore throat at day three is less than six, and at week one it is 18 5 or 21 6