Differential Diagnosis for 31-Year-Old Female with Unilateral Tonsillar Swelling and Exudate Without Fever
The absence of fever and cough in this patient strongly suggests a viral etiology rather than Group A streptococcal pharyngitis, but the unilateral presentation with tonsillar spots warrants consideration of infectious mononucleosis, other bacterial causes including Groups C/G streptococci, and potentially serious conditions like peritonsillar abscess or Lemierre's syndrome. 1, 2
Primary Differential Considerations
Viral Etiologies (Most Likely)
Infectious Mononucleosis (Epstein-Barr Virus)
- The patient's age (31 years, young adult) and presentation with tonsillar exudate without fever fits the classic EBV profile 1, 2
- EBV frequently causes acute pharyngitis with tonsillar involvement and is particularly common in teenagers and young adults 1
- Look for generalized lymphadenopathy beyond anterior cervical nodes and possible splenomegaly 1
- Critical pitfall: If EBV is suspected, avoid amoxicillin/ampicillin as these can cause severe maculopapular rash in 80-90% of EBV patients 2, 3
Other Viral Causes
- Adenovirus, herpes simplex virus, coxsackievirus, and other respiratory viruses can cause tonsillar inflammation with exudate 1, 2
- The absence of cough, rhinorrhea, conjunctivitis, and hoarseness makes common respiratory viruses less likely 1, 2
Bacterial Etiologies
Group A Streptococcus (Less Likely but Must Exclude)
- While the absence of fever argues strongly against GAS pharyngitis, it cannot be completely excluded on clinical grounds alone 1
- The patient's age (31 years) is outside the typical peak age range of 5-15 years, making GAS less probable 1, 4
- However, GAS is the only common bacterial cause requiring definitive antibiotic treatment to prevent rheumatic fever and glomerulonephritis 1, 5
Groups C and G Beta-Hemolytic Streptococci
- These organisms can cause severe pharyngitis with tonsillar exudate, particularly in young adults 1, 6
- A case report of a 30-year-old woman with Group C streptococcal pharyngitis presented with progressive symptoms over 9 days despite negative rapid strep tests 6
- Prevalence is approximately 5% in adults 6
Arcanobacterium haemolyticum
- Particularly common in teenagers and young adults 1
- Often associated with a scarlatiniform rash 1
- More commonly recognized in Scandinavia and UK, but should be considered 1
Neisseria gonorrhoeae
- Must be considered in sexually active individuals, especially with unilateral tonsillar involvement 1
- Obtain sexual history to assess risk 1
Serious Conditions Requiring Urgent Evaluation
Peritonsillar Abscess
- Unilateral tonsillar swelling is a red flag for abscess formation 6
- Look for uvular deviation away from the affected side, trismus, "hot potato voice," and severe unilateral throat pain 6
- May require CT imaging if clinical suspicion is high 6
Lemierre's Syndrome (Fusobacterium necrophorum)
- This is a potentially life-threatening condition that can present initially as simple pharyngitis 7
- Suspect if there is painful neck swelling, particularly along the sternocleidomastoid muscle (indicating internal jugular vein thrombophlebitis) 7
- More common in previously healthy young adults 7
- Critical teaching point: Exclusion of streptococcal infection does not exclude a serious bacterial cause 7
Diagnostic Approach
Immediate Clinical Assessment
- Examine for uvular deviation, trismus, and asymmetric tonsillar swelling suggesting abscess 6
- Palpate neck carefully for painful swelling along the sternocleidomastoid (Lemierre's syndrome) 7
- Check for generalized lymphadenopathy and splenomegaly (EBV) 1
- Assess for scarlatiniform rash (Arcanobacterium) 1
Laboratory Testing Required
Microbiological confirmation is mandatory because clinical features alone cannot reliably differentiate bacterial from viral causes 1, 2
Perform rapid antigen detection test (RADT) for Group A streptococcus 1, 2
Throat culture on blood agar plate 1
Consider heterophile antibody test (Monospot) or EBV serology if clinical suspicion for infectious mononucleosis is high 1, 2
Blood cultures if patient appears toxic or has neck swelling to rule out Lemierre's syndrome 7
When NOT to Test
Testing is not recommended if obvious viral features are present (cough, rhinorrhea, conjunctivitis, oral ulcers, hoarseness) 1, 2, 4
Management Algorithm
If RADT/Culture Positive for GAS
- Penicillin V 250-500 mg orally 2-3 times daily for 10 days OR amoxicillin 500 mg twice daily for 10 days 1, 3
- Avoid amoxicillin if EBV cannot be excluded 2, 3
- For penicillin allergy: first-generation cephalosporin, clindamycin, clarithromycin, or azithromycin 1
If Testing Negative or Viral Etiology Confirmed
- Antibiotics are NOT indicated 2, 8
- Supportive care only: ibuprofen or acetaminophen for pain, adequate hydration, warm saline gargles 2, 3, 8
- Counsel that symptoms typically resolve within 7 days 3
If Peritonsillar Abscess or Lemierre's Syndrome Suspected
- Urgent ENT consultation or hospital admission 6, 7
- CT imaging may be required 6
- Broad-spectrum IV antibiotics covering anaerobes 7
Key Clinical Pitfalls to Avoid
- Do not assume absence of fever excludes bacterial infection entirely, though it makes viral causes much more likely 1, 2
- Unilateral tonsillar swelling requires careful evaluation for abscess or other serious pathology 6
- Negative rapid strep test does not exclude all bacterial causes, particularly Groups C/G streptococci 6
- Always examine the neck carefully for painful swelling that could indicate Lemierre's syndrome 7
- Never prescribe amoxicillin empirically without excluding EBV in young adults with tonsillar exudate 2, 3
- Do not treat empirically without microbiological confirmation unless patient meets criteria for presumptive treatment 1, 2