Strep Throat Symptoms: Signs, Symptoms & What to Expect

Strep throat (streptococcal pharyngitis) is caused by Streptococcus pyogenes (Group A Strep). It accounts for 15-30% of sore throats in children and 5-15% in adults.

Classic Symptoms (Centor Criteria)

• Fever ≥38°C (100.4°F)
• Tonsillar exudates (white/yellow patches)
• Tender anterior cervical lymphadenopathy
• Absence of cough (cough suggests viral etiology)

3-4 criteria = high probability; 0-1 = low probability (testing not routinely needed).

Additional Common Symptoms

• Sudden-onset severe sore throat (painful swallowing)
• Headache
• Abdominal pain, nausea, vomiting (especially children)
• Scarlet fever rash (sandpaper-like, starts on trunk) – due to erythrogenic toxin
• Palatal petechiae (tiny red spots on soft palate)
• Fatigue, malaise

Symptoms Suggesting VIRAL Etiology (Not Strep)

• Cough, rhinorrhea, hoarseness, conjunctivitis, diarrhea, discrete oral ulcers (herpangina, coxsackie).

Diagnosis

• Rapid antigen detection test (RADT): Specific (~95%), sensitivity 70-90%.
• Throat culture: Gold standard (90-95% sensitive), 24-48 hours.
• Molecular (NAAT): Highly sensitive/specific, faster than culture.

Treatment

• Penicillin or amoxicillin (10 days) – first-line, narrow-spectrum, prevents rheumatic fever.
• Alternatives for penicillin allergy: cephalexin, azithromycin, clindamycin.
• Symptomatic relief: analgesics, hydration, soft foods.
• Contagious until 24 hours on antibiotics.

Complications (if untreated)

• Suppurative: peritonsillar abscess, sinusitis, otitis media.
• Non-suppurative: acute rheumatic fever (heart, joints, brain), post-streptococcal glomerulonephritis.

See a clinician for testing if Centor criteria ≥2, or if symptoms are severe/prolonged.