What is the recommended treatment for a patient with a clinical presentation suggestive of streptococcal (strep) pharyngitis but a negative rapid strep test?

Management of Pharyngitis with Negative Rapid Strep Test

In adults, withhold antibiotics and provide symptomatic care only when the rapid strep test is negative, as this result is sufficient to rule out group A streptococcal pharyngitis. 1

Age-Based Diagnostic Algorithm

Adults

• A negative RADT alone is adequate—do not order a backup throat culture 1, 2
• The specificity of RADT is ≥95%, making false positives rare, while adults have only 5-10% prevalence of streptococcal pharyngitis and extremely low risk of acute rheumatic fever 2, 3
• Routine backup cultures in adults are not necessary according to IDSA guidelines (strong recommendation, moderate evidence) 1

Children and Adolescents

• Send a backup throat culture after any negative RADT before making final treatment decisions 1, 2
• RADT sensitivity is only 80-90% in this age group, missing 10-20% of true infections 2, 4
• Treatment can be safely initiated within 9 days of symptom onset if the culture returns positive, which still effectively prevents acute rheumatic fever 2, 3
• The higher prevalence of streptococcal pharyngitis (20-30%) in children ages 5-15 justifies the backup culture approach 2

Children Under 3 Years

• Do not test or treat for streptococcal pharyngitis in this age group 1, 4
• Acute rheumatic fever is rare and the incidence of streptococcal pharyngitis is uncommon in children under 3 1
• Exception: Consider testing if risk factors exist, such as an older sibling with confirmed GAS infection 1, 4

Symptomatic Management While Awaiting Culture Results

Provide analgesics/antipyretics for symptom relief rather than antibiotics 1, 2, 3

• Offer ibuprofen or acetaminophen for moderate to severe symptoms (strong recommendation, high evidence) 1, 2
• Avoid aspirin in children (strong recommendation, moderate evidence) 1
• Reassure patients that symptoms typically resolve in less than 1 week without antibiotics 2, 3
• Antibiotics shorten sore throat duration by only 1-2 days, with a number needed to treat of 6 at 3 days and 21 at 1 week 2, 3

What NOT to Do: Common Pitfalls

Do not prescribe antibiotics empirically based on clinical appearance alone 2, 4

• White patches and exudate occur with viral infections and do not reliably distinguish bacterial from viral causes 2
• Up to 70% of patients with sore throats receive unnecessary antibiotic prescriptions, while only 20-30% actually have streptococcal pharyngitis 2

Do not test or treat asymptomatic household contacts 1, 2

• Up to one-third of households include asymptomatic carriers of group A streptococcus 2
• Antibiotic prophylaxis of household contacts has not been shown to reduce subsequent infection incidence 2

Do not order follow-up cultures after treatment in asymptomatic patients 1

• Routine post-treatment testing is not recommended unless special circumstances exist 1, 4

Clinical Features Suggesting Viral Etiology

When viral features are present, the negative RADT confirms you should not treat with antibiotics 1, 2

Viral indicators include:

• Rhinorrhea (runny nose) 1, 2
• Cough 1, 5
• Hoarseness 1
• Conjunctivitis 4
• Oral ulcers 1
• Diarrhea 4

The presence of rhinorrhea in children strongly suggests viral etiology, making streptococcal pharyngitis less likely 2

If Culture Returns Positive After Initial Negative RADT

Initiate antibiotic therapy with penicillin or amoxicillin for 10 days 1

• Penicillin or amoxicillin remains the treatment of choice based on narrow spectrum, safety, and low cost (strong recommendation, high evidence) 1
• For penicillin-allergic patients (non-anaphylactic): first-generation cephalosporin for 10 days 1, 5
• For anaphylactic penicillin allergy: clindamycin or clarithromycin for 10 days, or azithromycin for 5 days (strong recommendation, moderate evidence) 1
• Note significant resistance to azithromycin and clarithromycin exists in some U.S. regions 6, 5

Rationale for This Conservative Approach

The primary justification for treating confirmed streptococcal pharyngitis is prevention of acute rheumatic fever, not symptom relief 2, 3

• Antibiotics do not prevent post-streptococcal glomerulonephritis 2
• Treatment within 9 days of symptom onset still effectively prevents acute rheumatic fever 2, 3
• The risk-benefit ratio favors withholding antibiotics when tests are negative, given the minimal symptom benefit (1-2 days) versus risks of adverse effects and antibiotic resistance 2, 3