Tonsillitis

Causes

Viral tonsillitis (most cases)

• cold viruses (rhinovirus, coronavirus)
• adenovirus, often with red eyes
• influenza
• Epstein-Barr virus, causing mononucleosis
• enteroviruses and herpes viruses

Bacterial tonsillitis

• Group A Streptococcus (strep throat): most common bacterial cause, especially in children aged 5 to 15
• rarely, other bacteria such as group C or G strep, Fusobacterium, gonorrhea and diphtheria (very rare in vaccinated people)

Symptoms

• sore throat and pain when swallowing
• red, swollen tonsils, sometimes with white or yellow patches (exudate)
• fever
• tender, swollen lymph nodes in the neck
• bad breath
• ear pain from referred pain
• headache, stomachache and vomiting, especially in children
• a scratchy or muffled voice

Strep vs viral tonsillitis

Doctors use scoring systems such as the Centor or McIsaac score to decide who needs a strep test. Symptoms alone cannot reliably tell strep from a virus.

Diagnosis

• Examination of the throat, neck glands and ears
• Rapid strep test (results in minutes) and, in children and teens with a negative rapid test, a throat culture
• Mono test and blood count if mononucleosis is suspected
• CT or ultrasound if an abscess is possible

Testing is not usually recommended for children under 3 or when clear viral symptoms are present, because strep is uncommon in those situations.

Treatment

Home care

• rest and plenty of fluids
• cold drinks, ice pops or warm drinks, whichever soothes more
• soft foods
• saltwater gargles for older children and adults
• throat lozenges for older children and adults (choking risk in young children)
• humidified air
• pain relief: acetaminophen (paracetamol) or ibuprofen, following the label dose. Do not give aspirin to children or teenagers.

Antibiotics

Antibiotics are needed only for confirmed bacterial tonsillitis, mainly strep. Penicillin or amoxicillin, usually for 10 days, is first-line. Alternatives are used for penicillin allergy. Antibiotics shorten strep illness by about a day, reduce spread, and prevent complications such as rheumatic fever. Finish the full course.

Steroids

A single dose of a steroid is sometimes given for severe pain or swelling in adults.

Tonsillectomy

Removal of the tonsils may be considered for:

• frequent sore throat episodes: at least 7 in the past year, 5 a year for 2 years, or 3 a year for 3 years, each documented with fever, swollen glands, exudate or a positive strep test
• recurrent peritonsillar abscess
• obstructive sleep apnea due to enlarged tonsils, especially in children

Recovery typically takes 1 to 2 weeks, with throat pain and a risk of bleeding up to about 2 weeks after surgery.

Complications

• peritonsillar abscess (quinsy)
• scarlet fever
• ear infections and sinusitis
• dehydration
• rare after strep: rheumatic fever and post-streptococcal glomerulonephritis
• airway obstruction in severe swelling (rare)

Is tonsillitis contagious?

Yes. The viruses and bacteria that cause tonsillitis spread through droplets from coughs, sneezes and shared cups or utensils. People with strep are generally no longer contagious after 12 to 24 hours of antibiotics and can return to school or work once fever-free.

Prevention

• wash hands often
• avoid sharing drinks, cups and utensils
• cover coughs and sneezes
• replace your toothbrush after a strep infection

Frequently asked questions

How long does tonsillitis last?

Viral tonsillitis usually improves within 3 to 7 days. Strep tonsillitis improves within 1 to 2 days of starting antibiotics. Mononucleosis can cause sore throat and tiredness for 2 weeks or more. See a doctor if symptoms last more than a week.

What is the difference between tonsillitis and strep throat?

Tonsillitis means inflamed tonsils from any cause, usually a virus. Strep throat is an infection caused by group A strep bacteria, which often inflames the tonsils. Only a test can confirm strep, which needs antibiotics.

Is tonsillitis contagious?

Yes. The germs that cause tonsillitis spread through respiratory droplets and shared items. People with strep stop being contagious after about 12 to 24 hours of antibiotics. Viral tonsillitis is contagious while symptoms are present.

Do I need antibiotics for tonsillitis?

Only if a bacterial cause such as strep is confirmed. Most tonsillitis is viral, and antibiotics do not help viral infections. A rapid strep test or throat culture helps decide.

When is a tonsillectomy recommended?

Tonsillectomy may be recommended for frequent, documented tonsillitis (such as 7 or more episodes in one year), recurrent peritonsillar abscesses, or sleep apnea caused by large tonsils. Many children with occasional tonsillitis improve as they grow.