Published: 18 Jun 2025

ICD9: 034.0      ICD10: J02.0      ICD11: 1B51

Strep throat is a bacterial infection of the throat and tonsils.
It's caused by a bacteria called *Streptococcus pyogenes*, often referred to as group A strep.

Here's a breakdown of what you need to know:

Symptoms:

Sore throat: Often comes on quickly and can be quite painful.
Painful swallowing: Makes it difficult to eat or drink.
Red and swollen tonsils: Often with white patches or streaks of pus.
Tiny red spots on the roof of the mouth (petichiae): This is a common sign.
Swollen lymph nodes in the neck: These may be tender to the touch.
Fever: Usually above 101°F (38.3°C).
Headache
Stomachache, nausea, or vomiting: More common in children.
Rash (scarlet fever): A fine, red rash that feels like sandpaper can sometimes occur, particularly in children. This is called scarlet fever.

Causes:

Bacteria: *Streptococcus pyogenes* (group A strep) is the culprit.
Contagious: Strep throat is highly contagious and spreads through respiratory droplets, such as when someone coughs or sneezes. You can also get it by sharing food or drinks with someone who has strep.

Diagnosis:

Physical exam: A doctor will examine the throat and check for other symptoms.
Rapid strep test: This test involves swabbing the back of the throat and testing it for the presence of strep bacteria. Results are usually available quickly.
Throat culture: If the rapid strep test is negative but the doctor still suspects strep throat, a throat culture may be performed. This involves sending the swab to a lab to see if strep bacteria grows. Results take longer (24-48 hours).

Treatment:

Antibiotics: Strep throat is treated with antibiotics, usually penicillin or amoxicillin. If you're allergic to penicillin, other antibiotics like azithromycin or cephalexin may be prescribed.
Complete the full course of antibiotics: It's crucial to take all the medication prescribed, even if you start feeling better. This helps prevent complications.
Pain relief: Over-the-counter pain relievers like ibuprofen (Advil, Motrin) or acetaminophen (Tylenol) can help relieve pain and fever.
Home care:
Rest: Get plenty of rest to allow your body to heal.
Stay hydrated: Drink plenty of fluids, especially water, to prevent dehydration.
Gargle with warm salt water: This can help soothe a sore throat.
Eat soft foods: Avoid foods that are hard or difficult to swallow.
Use a humidifier: This can help keep the air moist and reduce throat irritation.

Complications (If Untreated):

It's very important to get strep throat treated with antibiotics. Untreated strep throat can lead to serious complications, including:

Rheumatic fever: A serious inflammatory condition that can affect the heart, joints, brain, and skin. Can lead to permanent heart damage (rheumatic heart disease).
Glomerulonephritis: A kidney disorder.
Peritonsillar abscess: A collection of pus behind the tonsils.
Scarlet fever: As mentioned earlier, a rash can develop. While treatable with antibiotics, it is a complication of strep.

Prevention:

Wash your hands frequently: Use soap and water for at least 20 seconds.
Avoid sharing food, drinks, and utensils:
Cover your mouth and nose when you cough or sneeze: Use a tissue or your elbow.
Stay home if you're sick: To prevent spreading the infection to others.

When to see a doctor:

It's important to see a doctor if you suspect you have strep throat. Specifically, see a doctor if you have:

A severe sore throat that comes on quickly.
Painful swallowing.
Red and swollen tonsils, especially with white patches or pus.
Swollen lymph nodes in your neck.
Fever.
A rash.

Important Note: While many sore throats are caused by viruses (like the common cold), it's important to rule out strep throat, as it requires antibiotic treatment. Don't self-diagnose or self-treat. Always see a doctor for proper diagnosis and treatment.