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 tonsillitis occurs frequently, doesn't respond to other treatments or causes serious complications.

Tonsillitis most commonly affects children between preschool ages and the midteenage 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
• Fever
• Enlarged, tender glands (lymph nodes) in the neck
• A scratchy, muffled or throaty voice
• Bad breath
• Stomachache
• Neck pain or stiff neck
• Headache

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 with fever
• 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 signs:

• Difficulty breathing
• Extreme difficulty swallowing
• Excessive drooling

Tonsillitis is most often caused by common viruses, but bacterial infections also can 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 affects children, and tonsillitis caused by bacteria is most common in children ages 5 to 15.
• 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:

• 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)

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 disorders such as:

• Rheumatic fever, a serious inflammatory condition that can affect the heart, joints, nervous system and skin
• Complications of scarlet fever, a streptococcal infection characterized by a prominent rash
• Inflammation of the kidney (poststreptococcal glomerulonephritis)
• Poststreptococcal reactive arthritis, a condition that causes inflammation of the joints

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

Your child's doctor will start with a physical exam that will include:

• Using a lighted instrument to look at your child's throat and likely his or her ears and nose, which also may be sites of infection
• Checking for a rash known as scarlatina, which is associated with some cases of strep throat
• Gently feeling (palpating) your child's neck to check for swollen glands (lymph nodes)
• Listening to his or her breathing with a stethoscope
• Checking for enlargement of the spleen (for consideration of mononucleosis, which also inflames the tonsils)

Throat swab

With this simple test, the doctor rubs a sterile swab over the back of your child's throat to get a sample of secretions. The sample will be checked in the clinic or in a lab for 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 often return results within several hours or a couple of days.

If the rapid in-clinic test comes back positive, then your child almost certainly has a bacterial infection. If the test comes back negative, then your child likely has a viral infection. Your doctor will wait, however, for the more reliable out-of-clinic lab test to determine the cause of the infection.

Complete blood cell count (CBC)

Your doctor may order a CBC with a small sample of your child's blood. The result of this test, which can often be completed in a clinic, produces a count of the different types of blood cells. The profile of what's elevated, what's normal or what's below normal can indicate whether an infection is more likely caused by a bacterial or viral agent. A CBC is not often needed to diagnose strep throat. However, if the strep throat lab test is negative, the CBC may be needed to help determine the cause of tonsillitis.

At-home care

Whether tonsillitis is caused by a viral or bacterial infection, at-home care strategies can make your child more comfortable and promote better recovery.

If a virus is the expected cause of tonsillitis, these strategies are the only treatment. Your doctor won't prescribe antibiotics. Your child will likely be better within seven to 10 days.

At-home care strategies to use during the recovery time include the following:

• Encourage rest. Encourage your child to get plenty of sleep.
• Provide adequate fluids. Give your child plenty of water to keep his or her throat moist and prevent dehydration.
• Provide comforting foods and beverage. Warm liquids — broth, caffeine-free tea or warm water with honey — and cold treats like ice pops can soothe a sore throat.
• Prepare a saltwater gargle. If your child can gargle, a saltwater gargle of 1/2 teaspoon (2.5 milliliters) of table salt to 8 ounces (237 milliliters) of warm water can help soothe a sore throat. Have your child gargle the solution and then spit it out.
• Humidify the air. Use a cool-air humidifier to eliminate dry air that may further irritate a sore throat, or sit with your child for several minutes in a steamy bathroom.
• Offer lozenges. Children older than age 4 can suck on lozenges to relieve a sore throat.
• Avoid irritants. Keep your home free from cigarette smoke and cleaning products that can irritate the throat.

• Treat pain and fever. Talk to your doctor about using ibuprofen (Advil, Children's Motrin, others) or acetaminophen (Tylenol, others) to minimize throat pain and control a fever. Low fevers without pain do not require treatment.

  Unless aspirin is prescribed by a doctor to treat a particular disease, children and teenagers should not take aspirin. Aspirin use by children to treat symptoms of cold or flu-like illnesses has been linked to Reye's syndrome, a rare but potentially life-threatening condition.

Antibiotics

If tonsillitis is caused by a bacterial infection, your doctor will prescribe a course of antibiotics. Penicillin taken by mouth for 10 days is the most common antibiotic treatment prescribed for tonsillitis caused by group A streptococcus. If your child is allergic to penicillin, your doctor will prescribe an alternative antibiotic.

Your child must take the full course of antibiotics as prescribed even if the symptoms go away completely. Failure to take all of the medication as directed may result in the infection worsening or spreading to other parts of the body. Not completing the full course of antibiotics can, in particular, increase your child's risk of rheumatic fever and serious kidney inflammation.

Talk to your doctor or pharmacist about what to do if you forget to give your child a dose.

Surgery

Surgery to remove tonsils (tonsillectomy) may be used to treat frequently recurring tonsillitis, chronic tonsillitis or bacterial tonsillitis that doesn't respond to antibiotic treatment. Frequent tonsillitis is generally defined as:

• At least seven episodes in the preceding year
• At least five episodes a year in the past two years
• At least three episodes a year in the past three years

A tonsillectomy may also be performed if tonsillitis results in difficult-to-manage complications, such as:

• Obstructive sleep apnea
• Breathing difficulty
• Swallowing difficulty, especially meats and other chunky foods
• An abscess that doesn't improve with antibiotic treatment

A tonsillectomy is usually done as an outpatient procedure, unless your child is very young, has a complex medical condition or if complications arise during surgery. That means your child should be able to go home the day of the surgery. A complete recovery usually takes seven to 14 days.

If your child is experiencing a sore throat, difficulty swallowing or other symptoms that may indicate tonsillitis, you'll likely start with a visit to your family doctor or your child's pediatrician. You may be referred to a specialist in ear, nose and throat disorders.

Your doctor is likely to ask you a number of questions about your child's condition. Be prepared to answer the following questions:

• When did the symptoms begin?
• If your child has had a fever, what was his or her temperature?
• Does he or she have difficulty swallowing foods, or does it hurt to swallow?
• Does anything improve symptoms, such as an over-the-counter pain reliever or warm liquids?
• Has your child been diagnosed with tonsillitis or strep throat before? If so, when?
• Do symptoms seem to affect his or her sleep?
• Has your child been exposed to anyone known to have strep throat?

Questions you may want to ask your doctor include the following:

• How long will it take to get test results?
• What is the best course of treatment?
• Should I be concerned with how frequently my child is getting tonsillitis?
• When can my child go back to school or resume other activities?