Acute Tonsillitis

What the tonsils do

The tonsils are part of the immune system and help trap germs entering through the mouth and nose. They are largest in childhood and shrink in adulthood. Because they are frontline immune tissue, they often become infected, especially in children aged 5 to 15.

Symptoms

• sore throat, often severe, with pain on swallowing
• red, swollen tonsils, sometimes with white or yellow patches or spots of pus
• fever and chills
• tender, swollen lymph nodes in the neck
• ear pain (referred from the throat)
• bad breath, headache and tiredness
• in young children: drooling, refusing food, tummy pain and vomiting

Viral vs bacterial tonsillitis

Doctors use scores such as Centor or McIsaac (fever, no cough, swollen tender neck glands, pus on the tonsils, and age) to decide who needs a strep test. White patches alone do not prove strep; they are common with viruses, including glandular fever (infectious mononucleosis).

Causes

• Viruses: rhinovirus, adenovirus, influenza, coronaviruses, Epstein-Barr virus (glandular fever) and enteroviruses.
• Bacteria: group A Streptococcus is the main bacterial cause (strep throat). Rarely others, including gonorrhea or diphtheria in unvaccinated people.

The infection spreads through droplets from coughs and sneezes and from shared cups and utensils.

Diagnosis

• Examination of the throat, neck glands and ears.
• Rapid antigen detection test (rapid strep test): a throat swab with results in minutes. In children and teens, a negative rapid test is usually confirmed with a throat culture. In adults, a negative rapid test is generally enough.
• Monospot or EBV blood tests if glandular fever is suspected.

US guidelines advise against strep testing when there are clear viral features such as cough and runny nose.

Treatment

Home care for all tonsillitis

• Pain relief: acetaminophen (paracetamol) or ibuprofen, following the label dose. Do not give aspirin to children or teenagers.
• Fluids: cool drinks, ice pops and soft foods. Staying hydrated matters more than eating.
• Throat soothers: warm salt water gargles (for older children and adults), lozenges for those old enough not to choke, and honey for anyone over 1 year.
• Rest.

Antibiotics for strep

Confirmed strep tonsillitis is treated with penicillin or amoxicillin for 10 days, or alternatives for people with penicillin allergy. Antibiotics shorten symptoms by about a day, reduce spread, and prevent complications such as rheumatic fever. People are usually no longer contagious after 12 to 24 hours of antibiotics.

Antibiotics do not help viral tonsillitis. Amoxicillin given during glandular fever often causes a widespread rash.

Steroids

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

How long acute tonsillitis lasts

Viral tonsillitis usually improves within 3 to 7 days. Strep tonsillitis improves within 1 to 3 days of starting antibiotics. Glandular fever can cause tonsillitis for 1 to 2 weeks and tiredness for weeks longer.

Complications

• Peritonsillar abscess (quinsy): a pus collection beside one tonsil, with severe one-sided pain and trouble opening the mouth. It needs drainage.
• Ear infections and sinusitis.
• Scarlet fever: strep with a sandpaper-like rash.
• Rheumatic fever and post-streptococcal glomerulonephritis: rare complications of untreated strep.
• Airway obstruction: very rare, mainly with massive tonsil swelling in glandular fever.

When tonsillectomy is considered

Tonsil removal is considered for frequent, well-documented episodes: in children, guidelines use about 7 or more episodes in 1 year, 5 or more per year for 2 years, or 3 or more per year for 3 years, as well as recurrent peritonsillar abscess or sleep-disordered breathing from large tonsils. See chronic tonsillitis and tonsillitis.

Prevention

Wash hands often, avoid sharing cups and utensils, cover coughs, and keep children with strep home until they have had at least 12 hours of antibiotics and have no fever.

Frequently asked questions

How long does acute tonsillitis last?

Viral tonsillitis usually lasts 3 to 7 days. Strep tonsillitis starts improving within 1 to 3 days of antibiotics, but finish the full course. If you are not improving after a week, or symptoms get worse, see a doctor.

How can I tell if tonsillitis is viral or bacterial?

Viral tonsillitis often comes with a cough, runny nose and hoarseness. Strep is more likely with high fever, pus on the tonsils, tender swollen neck glands and no cough, especially in children aged 5 to 15. A rapid strep test confirms it.

Is acute tonsillitis contagious?

Yes. Both viral and bacterial tonsillitis spread through droplets and shared items. Strep is contagious until about 12 to 24 hours after starting antibiotics. Viral tonsillitis is contagious while symptoms are present, especially in the first few days.

Can adults get acute tonsillitis?

Yes, though it is more common in children. In adults, it is more often viral, and strep accounts for a smaller share of sore throats. Adults with a severe one-sided sore throat should watch for signs of a peritonsillar abscess.

Do white spots on tonsils mean strep?

Not necessarily. White or yellow patches occur with both viral and bacterial tonsillitis, including glandular fever. Only a strep test or throat culture can confirm strep. White spots without symptoms may be tonsil stones, which are harmless.