Tonsillitis is inflammation of the tonsils, two oval-shaped pads of tissue at the back of the throat — one tonsil on each side. Signs and symptoms of tonsillitis include swollen tonsils, sore throat, difficulty swallowing and tender lymph nodes on the sides of the neck.
Most cases of tonsillitis are caused by infection with a common virus, but bacterial infections also may cause tonsillitis.
Because appropriate treatment for tonsillitis depends on the cause, it's important to get a prompt and accurate diagnosis. Surgery to remove tonsils, once a common procedure to treat tonsillitis, is usually performed only when bacterial tonsillitis occurs frequently, doesn't respond to other treatments or causes serious complications.
Tonsillitis most commonly affects children between preschool ages and the mid-teenage years. Common signs and symptoms of tonsillitis include:
- Red, swollen tonsils
- White or yellow coating or patches on the tonsils
- Sore throat
- Difficult or painful swallowing
- Enlarged, tender glands (lymph nodes) in the neck
- A scratchy, muffled or throaty voice
- Bad breath
- Stomachache, particularly in younger children
- Stiff neck
In young children who are unable to describe how they feel, signs of tonsillitis may include:
- Drooling due to difficult or painful swallowing
- Refusal to eat
- Unusual fussiness
When to see a doctor
It's important to get an accurate diagnosis if your child has symptoms that may indicate tonsillitis.
Call your doctor if your child is experiencing:
- A sore throat that doesn't go away within 24 to 48 hours
- Painful or difficult swallowing
- Extreme weakness, fatigue or fussiness
Get immediate care if your child has any of these symptoms:
- Difficulty breathing
- Extreme difficulty swallowing
Tonsillitis is most often caused by common viruses, but bacterial infections can also be the cause.
The most common bacterium causing tonsillitis is Streptococcus pyogenes (group A streptococcus), the bacterium that causes strep throat. Other strains of strep and other bacteria also may cause tonsillitis.
Why do tonsils get infected?
The tonsils are the immune system's first line of defense against bacteria and viruses that enter your mouth. This function may make the tonsils particularly vulnerable to infection and inflammation. However, the tonsil's immune system function declines after puberty — a factor that may account for the rare cases of tonsillitis in adults.
Risk factors for tonsillitis include:
- Young age. Tonsillitis most often occurs in children, but rarely in those younger than age 2. Tonsillitis caused by bacteria is most common in children ages 5 to 15, while viral tonsillitis is more common in younger children.
- Frequent exposure to germs. School-age children are in close contact with their peers and frequently exposed to viruses or bacteria that can cause tonsillitis.
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 (tonsillar cellulitis)
- Infection that results in a collection of pus behind a tonsil (peritonsillar abscess)
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 disorders 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
The germs that cause viral and bacterial tonsillitis are contagious. Therefore, the best prevention is to practice good hygiene. Teach your child to:
- Wash his or her hands thoroughly and frequently, especially after using the toilet and before eating
- Avoid sharing food, drinking glasses, water bottles or utensils
- Replace his or her toothbrush after being diagnosed with tonsillitis
To help your child prevent the spread of a bacterial or viral infection to others:
- Keep your child at home when he or she is ill
- Ask your doctor when it's all right for your child to return to school
- Teach your child to cough or sneeze into a tissue or, when necessary, into his or her elbow
- Teach your child to wash his or her hands after sneezing or coughing