Tonsillitis Diagnosis

Tonsillitis can be diagnosed⁹ through several physical exams. You or your child’s provider is always the best person who can provide an accurate diagnosis.

Do I have tonsillitis?

Your provider will start with a physical exam that will include:

• Using a lighted instrument to look at your throat and likely your ears and nose, which may also be sites of infection
• Checking for a rash that may indicate scarlet fever (a complication of strep throat)
• Gently feeling (palpating) your neck to check for swollen glands (lymph nodes)
• Listening to your breathing with a stethoscope
• Checking for enlargement of the spleen (to rule out mononucleosis, which can also cause tonsillitis)
• Throat swab. With this test, your provider will swab the back of your throat for a sample to test for the presence of streptococcal bacteria.

Many clinics are equipped with a lab that can get a test result within a few minutes. However, a second more reliable test is usually sent out to a lab that can return results within 24 to 48 hours.

If the rapid in-clinic test comes back positive, then you almost certainly have a bacterial infection. If the test comes back negative, then you likely have a viral infection. Your provider may wait, however, for the more reliable out-of-clinic lab test results to determine the cause of the infection.

Your provider may also order a complete blood cell count with a small sample of your blood. The result of this test, which can often be completed in a clinic, produces a count of the different types of blood cells in your body. Abnormal counts of various blood cells types can indicate whether an infection is more likely caused by a bacterial or viral agent.

Complications from tonsillitis

Although rare, inflammation or swelling of the tonsils from frequent or ongoing (chronic) tonsillitis can cause complications such as:

• Difficulty breathing
• Disrupted breathing during sleep (obstructive sleep apnea)
• Infection that spreads deep into surrounding tissue, such as in the throat and chest area (tonsillar cellulitis)
• Infection that results in a collection of pus behind the tonsils (peritonsillar abscess)
• Strep infection

If tonsillitis caused by group A streptococcus or another strain of streptococcal bacteria isn't treated, or if antibiotic treatment is incomplete, your child has an increased risk of rare complications such as:

• Rheumatic fever, an inflammatory disorder that affects the heart, joints and other tissues
• Poststreptococcal glomerulonephritis, an inflammatory disorder of the kidneys that results in inadequate removal of waste and excess fluids from blood.