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What You Need to Know about Strep Throat

Jul 19, 2021
Child having throat medically examined.

You’ve probably heard of strep throat, but what exactly is this common condition? Read on to find out!

What Causes Strep Throat?

Strep throat is caused by a specific bacterial organism called group A beta-hemolytic streptococcus pyogenes. This organism lives in the nose and throat of many people. In its dormant state, group A strep does not cause symptoms. However, when this organism becomes active, it can invade into deeper tissues, such as the tonsils. Group A strep is also easily spread from one person to another through nose and mouth secretions. So, you can get strep throat from your own dormant bacteria or from another person who has an active infection.

What Are the Signs and Symptoms of Strep Throat?

The most common symptom of group A strep infection is a sore throat. Fever, headache, and belly ache are also common. Tonsils are often red and swollen and they may be covered with white patches of pus. Red blotches on the roof of the mouth and swollen lymph nodes in the neck are also possible, and there may be an occasional cough. Some strains of group A strep also cause a distinctive rash. When this occurs, we call the illness “scarlet fever.” This may sound like a dangerous condition, but today’s scarlet fever is no more dangerous than your run-of-the-mill strep throat.

What Other Conditions Cause These Signs and Symptoms?

Viral infections also cause a sore throat. In particular, infections with adenovirus and Epstein-Barr virus (also known as Mono) can produce symptoms that are very similar to strep throat. Other viral illnesses, including the common cold, croup, RSV and COVID-19 may also result in a sore throat. These infections are more likely to produce nasal congestion and a persistent cough. On the other hand, it is possible to have a viral infection and strep throat at the same time. A simple visit to your doctor is the best way to tell if a sore throat is from group A strep, a virus or both.

How Is Strep Throat Diagnosed?

Strep throat is not diagnosed on symptoms alone. A throat swab and strep test are needed to correctly identify the condition. Rapid strep tests produce quick answers. However, some rapid tests require a second overnight test to improve their accuracy. If you have a negative rapid strep test, be sure to ask your doctor if a second overnight test is needed. Diagnosing strep with a test is important because true strep infections require treatment with an antibiotic. Viral sore throats are not treated with antibiotics. Using one with a viral infection may produce a rash and increase the risk of developing drug-resistant bacteria.

How Is Strep Throat Treated?

Although rare, group A strep infections can lead to a condition called rheumatic fever. Unlike scarlet fever, rheumatic fever is very serious. This occurs when your immune system begins attacking the heart, joints, brain, and skin following a group A strep infection. Treating strep throat with an antibiotic is the best way to prevent rheumatic fever. Antibiotics also stop the spread of strep from one person to another. Strep throat is no longer contagious about 12 hours after the first dose of medicine. Unfortunately, antibiotics only shorten the length of symptoms by a day or two. So, even after taking an antibiotic, you’ll likely have a sore throat for a few more days.

How Is Strep Throat Prevented?

There’s no good way to prevent dormant strep in your nose and throat from becoming active. It just happens! However, you can prevent the spread of strep from one person to another by staying home when you feel sick, washing hands often and keeping your distance from people with signs of illness.

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Nationwide Children's Hospital Medical Professional
Mike Patrick, MD
Emergency Medicine; Host of PediaCast

Dr Mike Patrick is an Assistant Professor of Pediatrics at the Ohio State University College of Medicine and Medical Director of Interactive Media for Nationwide Children's Hospital. Since 2006, he has hosted the award-winning PediaCast, a pediatric podcast for parents. Dr Mike also produces a national podcast for healthcare providers—PediaCast CME, which explores general pediatric and faculty development topics and offers free AMA PRA Category 1 Credit™ to listeners.

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700 Children’s® features the most current pediatric health care information and research from our pediatric experts – physicians and specialists who have seen it all. Many of them are parents and bring a special understanding to what our patients and families experience. If you have a child – or care for a child – 700 Children’s was created especially for you.