From the Guidelines
If you have visible pus or exudate on your tonsils but a negative strep test, you should still seek medical evaluation as this could indicate a viral infection or another bacterial infection besides strep. While waiting to see a healthcare provider, rest, stay hydrated, and take acetaminophen or ibuprofen for pain and fever. Your doctor may recommend watchful waiting with symptomatic treatment if a viral cause is suspected, or they might prescribe antibiotics like amoxicillin or azithromycin if they suspect a bacterial infection despite the negative test, as suggested by the American Academy of Otolaryngology-Head and Neck Surgery guidelines 1. Rapid strep tests can have false negatives (10-20%), so your doctor might order a throat culture for confirmation. The presence of tonsillar exudate along with fever, swollen lymph nodes, and absence of cough suggests a higher likelihood of strep throat even with a negative rapid test. Other possible causes include infectious mononucleosis, adenovirus, or other bacterial pathogens that wouldn't be detected by a strep test. According to the guidelines, tonsillectomy may be considered in recurrent throat infections if they have had at least seven documented episodes of sore throat in the previous year, at least five documented episodes in each of the previous two years, or at least three documented episodes in each of the previous three years, plus a temperature of greater than 100.9°F (38.3°C), cervical adenopathy, exudate, or a positive culture for group A β-hemolytic streptococcus 1. However, the most recent and highest quality study suggests that watchful waiting is appropriate for patients with recurrent throat infection who have a favorable natural history and are likely to improve without tonsillectomy 1. Key points to consider include:
- The patient's medical history and the frequency and severity of throat infections
- The presence of modifying factors that may make tonsillectomy favorable, such as multiple antibiotic allergies or specific clinical syndromes like PFAPA
- The potential benefits and harms of tonsillectomy, including the risk of complications and the potential improvement in quality of life. In general, watchful waiting with close monitoring and documentation of episodes is recommended for patients with recurrent throat infections who do not meet the criteria for tonsillectomy 1.
From the Research
Tonsils and Strep Test
- A negative strep test does not necessarily rule out tonsillitis, as the condition can be caused by viral infections in 70% to 95% of cases 2.
- Bacterial infections, such as group A beta-hemolytic streptococcus (Streptococcus pyogenes), account for tonsillitis in 5% to 15% of adults and 15% to 30% of patients five to 15 years of age 2.
- The diagnosis of streptococcal pharyngitis is typically made using a rapid antigen detection test, and treatment with penicillin or amoxicillin is recommended for 10 days 3, 4, 5.
Symptoms and Diagnosis
- Common signs and symptoms of streptococcal pharyngitis include sore throat, temperature greater than 100.4 degrees F (38 degrees C), tonsillar exudates, and cervical adenopathy 3.
- The modified Centor score can be used to help physicians decide which patients need no testing, throat culture/rapid antigen detection testing, or empiric antibiotic therapy 3, 4.
- A cough is more suggestive of a viral etiology, while fever, tonsillar exudate, cervical lymphadenitis, and patient ages of 3 to 15 years increase clinical suspicion of streptococcal pharyngitis 5.
Treatment and Management
- Penicillin and amoxicillin are first-line antibiotics for the treatment of streptococcal pharyngitis, with a recommended course of 10 days 3, 4, 5.
- First-generation cephalosporins are recommended for patients with nonanaphylactic allergies to penicillin 3, 5.
- Tonsillectomy is rarely recommended as a preventive measure, and is typically considered for patients with recurrent streptococcal pharyngitis, such as seven episodes in 1 year, five episodes in each of the past 2 years, or three episodes in each of the past 3 years 2, 5.