Do white spots on tonsils indicate a streptococcal (strep) infection?

White Spots on Tonsils Do Not Reliably Indicate Strep Infection

White spots or exudates on the tonsils can occur with both viral and bacterial infections and cannot reliably distinguish streptococcal pharyngitis from other causes—laboratory confirmation through rapid antigen detection testing (RADT) or throat culture is required for accurate diagnosis. 1, 2

Why Clinical Appearance Alone Is Insufficient

• The presence of tonsillopharyngeal exudates (white patches) may be present in streptococcal pharyngitis but is not required for diagnosis, and these findings overlap significantly with viral etiologies 3
• Viruses cause 70-95% of acute pharyngitis cases, including adenovirus, Epstein-Barr virus (infectious mononucleosis), and other common respiratory viruses—all of which can produce white patches and exudates 2, 4
• Even experienced clinicians cannot reliably distinguish streptococcal from viral pharyngitis based solely on physical examination findings 3
• Clinical scoring systems that incorporate multiple features (such as the Centor score) predict positive throat cultures with only 80% accuracy at best 1

The Actual Prevalence of Strep Throat

• Group A streptococcal pharyngitis accounts for only 15-30% of acute pharyngitis cases in children and just 5-10% in adults 1, 2
• This means that 70-85% of children and 90-95% of adults with pharyngitis have viral infections, even when white spots are present 2, 5
• Physicians overdiagnose streptococcal pharyngitis by a wide margin, leading to unnecessary antibiotic prescriptions in 60% or more of adults seeking care for sore throat 6, 5

Required Diagnostic Approach

Bacteriologic confirmation through RADT or throat culture should be performed before prescribing antibiotics, unless the diagnosis can be confidently excluded on clinical and epidemiologic grounds. 1

For Adults:

• A negative RADT alone is sufficient to rule out streptococcal pharyngitis—no backup throat culture is needed 1, 2
• The specificity of RADT is ≥95%, making false positives rare, while sensitivity is 80-90% 2

For Children and Adolescents:

• A negative RADT should be confirmed with a throat culture before making final treatment decisions, as the sensitivity of RADT is <90% in this age group 2, 5
• Treatment can be initiated if the culture returns positive—even delayed treatment within 9 days of symptom onset still prevents acute rheumatic fever 2

Proper Specimen Collection:

• Throat swab specimens must be obtained from both the tonsils (or tonsillar fossae) AND the posterior pharyngeal wall to maximize diagnostic accuracy 1, 7
• Improper swabbing technique is a major cause of false-negative results 1

Common Pitfall to Avoid

Do not prescribe antibiotics based on the appearance of white spots or exudates alone. 2 This practice leads to:

• Overtreatment of viral pharyngitis with unnecessary antibiotics 6, 5
• Increased antibiotic resistance 2
• Unnecessary adverse effects without clinical benefit 2
• Increased healthcare costs 6

When to Suspect Strep Throat

While laboratory confirmation is still required, the following features increase clinical suspicion for streptococcal pharyngitis:

• Sudden onset of sore throat 6
• Fever (typically high-grade) 3, 5
• Tender, enlarged anterior cervical lymph nodes 3, 5
• Tonsillopharyngeal erythema with or without exudates 3
• Patient age 3-15 years 3, 5
• Winter or early spring presentation 3
• Absence of viral features such as cough, rhinorrhea, conjunctivitis, hoarseness, or discrete ulcerative lesions 3, 5