1. Just a Sore Throat or Strep Slideshow
2. Take the Strep Throat Infection Quiz!
3. Infectious Mononucleosis Slideshow

Medical Author:

John Mersch, MD, FAAP

John Mersch, MD, FAAP

Dr. Mersch received his Bachelor of Arts degree from the University of California, San Diego, and prior to entering the University Of Southern California School Of Medicine, was a graduate student (attaining PhD candidate status) in Experimental Pathology at USC. He attended internship and residency at Children's Hospital Los Angeles.

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Medical Editor:

William C. Shiel Jr., MD, FACP, FACR

William C. Shiel Jr., MD, FACP, FACR

Dr. Shiel received a Bachelor of Science degree with honors from the University of Notre Dame. There he was involved in research in radiation biology and received the Huisking Scholarship. After graduating from St. Louis University School of Medicine, he completed his Internal Medicine residency and Rheumatology fellowship at the University of California, Irvine. He is board-certified in Internal Medicine and Rheumatology.

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Medical Editor:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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In this Article

• Strep throat facts
• What is strep throat?
• What causes a sore throat?
• What are tonsils and tonsillitis?
• What are pharynx and pharyngitis?
• Viral causes of throat infection
• Bacterial causes of throat infection
• How common is strep throat?
• Is strep throat contagious?
• What are the signs and symptoms of strep throat?
• Are strep throat symptoms different in children compared to adults?
• When should I be concerned about a possible strep throat?
• How is strep throat diagnosed?
• Who should be tested for strep throat?
• How is strep infection treated?
• How can viral throat infection be treated?
• Are there any recommended strep throat remedies and symptom reducers?
• When should the tonsils be removed?
• Why is it very important to detect and treat a strep throat?
• What are the potential complications of untreated strep throat infection?
• Is there a vaccine for strep throat?
• Can strep throat be prevented?
• Just a Sore Throat or Strep - Slideshow
• Take the Strep Throat Infection Quiz!
• Infectious Mononucleosis - Slideshow
• Strep Throat (Streptococcal) Infection FAQs
• Patient Comments: Strep Throat - Diagnosis
• Patient Comments: Strep Throat - Treatment
• Patient Comments: Strep Throat - Home Remedies for Symptoms
• Patient Comments: Strep Throat - Length Symptoms Lasted
• Strep Throat Index

Group A streptococcus is the most common bacterial cause of throat infection. Group A strep causes approximately 15% to 30% of cases of tonsillopharyngitis in children between 5 to 15 years of age. This age group (5 to 15 years old) has the peak incidence of strep throat infection. In adults, 5% to 10% of cases of pharyngitis are estimated to be caused by strep bacteria.

Some reports suggest that over 600 million cases of strep throat occur annually worldwide.

Yes, strep throat is contagious. The most common way to catch strep throat is by contact with an infected person.

Close contact with airborne droplets of an infected individual is the most common way of catching Streptococcus infection. Close quarters such as college dormitories, day care centers, military facilities, schools, and the family home provide ideal conditions for transmission of strep throat from one person to another. The risk of acquiring strep throat from an affected family member nears 40%. Spread through food-borne outbreaks is less common, but possible.

The risk of being contagious with strep throat diminishes substantially after initiation of proper antibiotic treatment.

The exact likelihood of contracting strep throat from family pets is unknown, but most experts say it is doubtful.

Throat infection with strep bacteria can cause a variety of symptoms associated with inflammation of the throat and its nearby structures. Symptoms usually begin within a few days (1-4 days) after exposure to the bacteria (incubation period).

With strep throat infection, the throat can become red and swollen. White patches may be visible on the back of the throat and the tonsils, suggesting the presence of pus. The presence of fever, swollen and often tender lymph nodes on the sides of the neck, and white patches on the tonsils along with the absence of cough raise the suspicion for strep pharyngitis. Not all of these signs need to be present with strep tonsillopharyngitis. On the other hand, their presence is not specific only to strep throat.

Typical signs of strep throat infection are:

• fever;
• swollen, tender lymph nodes on the sides of the neck (cervical lymphadenopathy);
• white patches seen on the tonsils and throat (tonsillar exudates).

Some other more non-specific signs and symptoms of strep throat which can also be seen in tonsillopharyngitis due to other causes are:

• sudden onset of sore throat,
• headache,
• odynophagia (painful swallowing),
• nausea, vomiting, abdominal pain,
• red, swollen soft palate (uvula), and/or
• rash (diffuse red patchy rash).

The strep throat rash is caused by toxins released from the bacteria, and not necessarily because of the spread of infection to the skin. A strep infection accompanied by this characteristic rash is what is known as "scarlet fever." Scarlet fever can occur in about 10% of children with a strep throat infection, and typically starts around the face and neck area and can spread to the chest, abdomen, and groin region. It has a classic description of "goose bumps on sunburned skin." The rash may start within 12 to 24 hours of the onset of fever and may last for several days. Peeling of the skin of the fingertips may accompany the rash of scarlet fever.

Other features that are more likely to be seen in tonsillopharyngitis due to viral causes include the following:

• conjunctivitis (eye redness),
• runny nose (coryza),
• skin rash (exanthem or small spotted rash),
• generalized weakness and malaise,
• muscle aches and pains,
• cough,
• hoarseness,
• diarrhea, and/or
• oral ulcers.