What are the symptoms and treatment options for a patient suspected of having strep throat?

Strep Throat: Symptoms and Treatment

Strep throat presents with sore throat, fever >100.4°F (38°C), tonsillar exudates, and tender anterior cervical lymphadenopathy, and should be treated with penicillin or amoxicillin for 10 days when laboratory-confirmed. 1, 2

Clinical Symptoms

Symptoms Suggesting Streptococcal Pharyngitis

• Sore throat with acute onset 1, 2
• Fever greater than 100.4°F (38°C) 2, 3
• Tonsillar exudates (white patches on tonsils) 2, 4
• Tender anterior cervical lymphadenopathy (swollen, painful neck lymph nodes) 2, 4
• Absence of cough (cough suggests viral etiology) 1, 4

Symptoms Suggesting Viral (Not Strep) Pharyngitis

• Cough is the strongest predictor of viral infection 1, 3
• Rhinorrhea (runny nose) 1
• Hoarseness 1
• Oral ulcers 1
• Diarrhea 2

Important caveat: The signs and symptoms of streptococcal and viral pharyngitis overlap so broadly that accurate diagnosis on clinical grounds alone is impossible—laboratory confirmation is essential. 1

Diagnosis

When to Test

• Use clinical decision rules (modified Centor score) to determine who needs testing 1, 3
• Do not test patients with clear viral symptoms (cough, rhinorrhea, hoarseness, oral ulcers) 1
• Do not test children under 3 years old, as strep pharyngitis is rare in this age group and acute rheumatic fever is exceptionally rare 1

Diagnostic Testing Approach

• Rapid antigen detection test (RADT) is the first-line test 1
• In children and adolescents: A negative RADT must be confirmed with throat culture due to 80-90% sensitivity 1, 5
• In adults: A negative RADT alone is sufficient to rule out strep throat—no backup culture needed due to low prevalence (5-10%) and extremely low risk of rheumatic fever 1, 5
• Throat culture remains the diagnostic gold standard with highest sensitivity 1

Critical pitfall: Never diagnose or treat based on symptoms alone without laboratory confirmation, as this leads to massive antibiotic overuse—60% of adults with sore throat receive antibiotics when only 10% actually have strep. 3, 5

Treatment

First-Line Antibiotic Therapy

Penicillin or amoxicillin for 10 days is the treatment of choice due to proven efficacy, safety, narrow spectrum, and low cost. 1

Specific dosing:

• Oral penicillin V: 250 mg 2-3 times daily (children) or 250 mg 4 times daily or 500 mg twice daily (adolescents/adults) for 10 days 6
• Amoxicillin: Equally effective and more palatable 1, 2
• Intramuscular benzathine penicillin G: Single dose of 600,000 units (<60 lb) or 1,200,000 units (>60 lb)—preferred when compliance with 10-day oral course is questionable 1, 6

Penicillin-Allergic Patients

• For non-anaphylactic penicillin allergy: First-generation cephalosporins (e.g., cephalexin 20 mg/kg twice daily, max 500 mg per dose) for 10 days 1, 6
• For immediate hypersensitivity/anaphylactic allergy: Azithromycin 12 mg/kg once daily (max 500 mg) for 5 days, clindamycin for 10 days, or clarithromycin for 10 days 1, 6

Important caveat: Azithromycin has significant resistance in some U.S. regions, and data establishing its efficacy in preventing rheumatic fever are not available. 7, 3

Symptomatic Treatment

• Acetaminophen or NSAIDs (ibuprofen) for moderate to severe symptoms or high fever 1, 5
• Avoid aspirin in children due to Reye's syndrome risk 1, 8
• Medicated throat lozenges every 2 hours are effective 4
• Corticosteroids are NOT recommended—they provide only minimal symptom reduction and do not address treatment goals 1, 8

Treatment Goals and Timing

Primary Treatment Objectives

1. Prevention of acute rheumatic fever (most important) 1
2. Prevention of suppurative complications (peritonsillar abscess, cervical lymphadenitis, mastoiditis) 1
3. Symptom resolution 1
4. Reduction in transmission to close contacts 1

Critical timing: Treatment can be safely delayed up to 9 days after symptom onset and still prevent acute rheumatic fever, allowing time for laboratory confirmation before starting antibiotics. 1, 5

Follow-Up and Special Circumstances

Post-Treatment Testing

• Routine follow-up cultures or RADTs are NOT recommended after completing appropriate antibiotic therapy in asymptomatic patients 1
• Exception: Consider follow-up testing in patients with history of rheumatic fever or during outbreaks in closed settings 1, 5

Household Contacts

• Do not test or treat asymptomatic household contacts—this is not recommended even with recurrent infections 1, 5
• Up to one-third of households include asymptomatic carriers who do not require treatment 5

Recurrent Episodes

• If multiple episodes occur with positive cultures at short intervals, consider that the patient may be a chronic carrier experiencing repeated viral infections rather than true recurrent strep infections 1, 5
• For documented recurrent infections, clindamycin or amoxicillin-clavulanate may achieve higher pharyngeal eradication rates 1, 6

Common pitfall: A positive test after treatment in an asymptomatic patient likely represents carrier state, not treatment failure—do not retreat based solely on positive test without symptoms. 1, 5