Strep Throat

Key takeaways

• Most common in: children aged 5 to 15
• Typical symptoms: sore throat that starts quickly, pain swallowing, fever, red swollen tonsils, swollen neck glands
• Most useful single change: See your doctor or urgent care for a strep test if you have a sore throat with fever and no cold symptoms.
• Commonest mistake: Using leftover antibiotics or someone else's prescription.
• See a doctor if any of the signs under "When to get help" below apply to you.

Why it matters

Unlike most sore throats, it is caused by bacteria and needs antibiotics, which shorten the illness, reduce spread and prevent rare complications such as rheumatic fever.

The numbers, in one place

Published figures for Strep Throat

Measure	Figure
Most common in	children aged 5 to 15
Typical symptoms	sore throat that starts quickly, pain swallowing, fever, red swollen tonsils, swollen neck glands
Signs that point to a virus instead	cough, runny nose, hoarseness and pink eye
Diagnosis	a rapid strep test or throat culture
Back to school or work	after the fever is gone and at least 12 hours of antibiotics

What helps

• See your doctor or urgent care for a strep test if you have a sore throat with fever and no cold symptoms
• Take every dose of the antibiotic for as long as prescribed, even after you feel better
• Use acetaminophen (Tylenol) or ibuprofen for pain, and drink cool fluids or eat soft foods
• Replace your toothbrush and do not share cups or utensils

What to avoid

• Using leftover antibiotics or someone else's prescription
• Stopping antibiotics early because the throat feels better
• Giving aspirin to children or teens

In depth

Group A Streptococcus bacteria attach to the lining of the throat and tonsils and release substances that trigger strong inflammation. That inflammation causes the sudden, painful sore throat, swollen tonsils and fever that set strep apart from most colds. The bacteria spread through droplets from coughs and sneezes and by sharing cups, utensils or food, and symptoms usually start two to five days after exposure.

Most sore throats are caused by viruses and get better on their own, so antibiotics do not help them. Strep throat is the main exception. Treating it with antibiotics shortens the illness, cuts the time you can spread it to others, and prevents complications such as an abscess near the tonsils and rheumatic fever, an immune reaction that can permanently damage the heart valves.

Some people with strep throat develop scarlet fever, a red, sandpaper-like rash that usually starts on the neck and chest, sometimes with a bright red tongue. It is caused by a toxin some strains make and is treated the same way. Some people carry group A strep in their throat without being ill; these carriers rarely spread it and usually do not need treatment.

Signs and symptoms

• A sore throat that comes on quickly rather than building over days
• Pain when swallowing
• Fever
• Red, swollen tonsils, sometimes with white patches or streaks of pus
• Tiny red spots on the roof of the mouth
• Tender, swollen glands in the front of the neck
• Headache, stomach ache, nausea or vomiting, especially in children

Causes and risk factors

• Close contact with someone who has strep throat
• Sharing cups, utensils, food or toothbrushes
• Crowded settings such as schools, child care centers and military barracks
• Being a school-age child, or an adult who lives or works with children
• Late fall through early spring, when it is most common
• Not covering coughs or washing hands regularly

How it is checked

You cannot tell strep from a viral sore throat by looking alone, so testing is the key step. A rapid strep test uses a quick throat swab and gives a result in minutes at a clinic, urgent care or some pharmacies. Because rapid tests can miss some infections, a negative result in a child or teen is usually followed by a throat culture, which takes a day or two. Adults usually do not need the culture.

Doctors generally do not test people whose symptoms point clearly to a virus, such as cough, runny nose, hoarseness or pink eye, or children under 3, in whom strep throat is uncommon. Testing people who have no symptoms after a family member is diagnosed is generally not recommended either, unless your doctor advises it for a specific reason.

Related topics

• Common Childhood Infections: What the Evidence Actually Says (Children's Health)
• The Evidence on Mouth Cancer Awareness, Without the Hype (Oral Health)
• Colds and Flu: What Published Guidance Supports (Immunity)
• Antibiotic Stewardship: Sorting the Evidence From the Noise (Medicines Safety)

Where to go next

• Strep Throat: The Quick Reference
• Strep Throat: What Published Guidance Supports
• Infectious Diseases: The Complete Guide
• Hepatitis A: Sorting the Evidence From the Noise
• The Evidence on Tuberculosis Basics, Without the Hype

When to get help

See your doctor if a sore throat lasts more than a few days, comes with a rash, or you do not improve after 48 hours of antibiotics. Call 911 for trouble breathing, being unable to swallow saliva or open the mouth fully, drooling, or a muffled voice with severe throat pain.

Where this comes from

• CDC — About Strep Throat
• MedlinePlus — Strep Throat

How this page was put together

Every figure, recommendation and warning above is taken from the guidance named in Where this comes from. Nothing on this page is inferred, summarized or generalized beyond what those bodies publish: where they give a number, it is their number, and where they are silent, so are we. Pages are rebuilt whenever the underlying record changes. Sign-off by a named clinician, where it has happened, is shown at the top of the page along with the date.

Medical disclaimer

This article is general information, not medical advice. It cannot account for your own history, medication or circumstances. Always speak to your doctor, pharmacist or another qualified health professional before making changes that affect your treatment, and never delay seeking medical advice because of something you have read here. In an emergency, call 911.