Streptococcal Pharyngitis
Streptococcal pharyngitis, also known as strep throat, is a bacterial infection caused by Streptococcus pyogenes, also referred to as Group A beta-hemolytic streptococcus (GABHS). It is one of the most common bacterial infections affecting the throat.
Cause and Transmission
The bacteria that cause streptococcal pharyngitis are highly contagious and can be spread through:
- Direct contact with an infected person's respiratory secretions, such as through kissing or sharing utensils
- Indirect contact with contaminated surfaces or objects
- Droplet transmission, where the bacteria are released into the air when an infected person coughs or sneezes
Symptoms
The symptoms of streptococcal pharyngitis typically develop within 2-5 days after exposure to the bacteria and may include:
- Sudden onset of a sore throat, which can be severe and is often accompanied by pain when swallowing
- Fever, usually high (over 101°F)
- Swollen, tender lymph nodes in the neck
- White or yellowish patches on the tonsils
- Red, swollen tonsils and throat
- Headache
- Stomachache
- Nausea and vomiting, especially in children
Diagnosis
Diagnosing streptococcal pharyngitis involves a combination of physical examination, medical history, and laboratory tests. The most common diagnostic tools include:
- Rapid streptococcal antigen test (RSA), which provides quick results but may not always be accurate
- Throat culture, which is more sensitive than RSA but takes longer to produce results (usually 24-48 hours)
- PCR (polymerase chain reaction) testing, a molecular diagnostic technique that can quickly and accurately identify the presence of GABHS DNA in throat swabs
Treatment
The primary treatment for streptococcal pharyngitis is antibiotics. The most commonly prescribed antibiotics are:
- Penicillin (such as amoxicillin or penicillin V)
- Amoxicillin-clavulanate
- Cephalexin or other cephalosporins, for individuals allergic to penicillin
- Azithromycin or clarithromycin, in cases of penicillin allergy and for patients who cannot tolerate cephalosporins
It is essential to complete the full course of antibiotics as prescribed by a healthcare provider, even if symptoms improve before finishing the medication. This helps prevent complications and reduces the risk of spreading the infection to others.
Complications
If left untreated or inadequately treated, streptococcal pharyngitis can lead to several complications, including:
- Acute rheumatic fever (ARF), a serious condition that can affect the heart, joints, skin, and brain
- Post-streptococcal glomerulonephritis (PSGN), an inflammatory disease of the kidneys
- Peritonsillar abscess, a collection of pus behind the tonsils that can cause severe pain and difficulty swallowing
- Mastoiditis, an infection of the mastoid bone in the skull
- Sinusitis, an infection of the sinuses
- Otitis media, an infection of the middle ear
Prevention
To reduce the risk of contracting streptococcal pharyngitis:
- Practice good hygiene by washing hands frequently with soap and water
- Avoid close contact with individuals who have a sore throat or are known to be infected
- Do not share utensils, glasses, or other personal items
- Cover the mouth and nose when coughing or sneezing
- Stay home from work or school if symptoms persist or worsen over time
Frequently Asked Questions (FAQs)
What is Streptococcal pharyngitis?
A bacterial infection of the throat caused by Group A Streptococcus.
What are the common symptoms of Streptococcal pharyngitis?
Sore throat, fever, swollen lymph nodes, and white patches on the tonsils.
How is Streptococcal pharyngitis typically diagnosed?
Through a rapid strep test or throat culture.
What is the treatment for Streptococcal pharyngitis?
Antibiotics, such as penicillin or amoxicillin, to help clear the infection.
Can Streptococcal pharyngitis be spread to others?
Yes, through close contact with an infected person's respiratory secretions.
How long is someone with Streptococcal pharyngitis contagious?
Usually until 24-48 hours after starting antibiotic treatment.
Can Streptococcal pharyngitis be prevented?
Possibly, by practicing good hygiene, such as frequent handwashing and avoiding close contact with infected individuals.
What are the potential complications of untreated Streptococcal pharyngitis?
May lead to conditions like rheumatic fever, kidney disease, or abscesses.
How long does it usually take to recover from Streptococcal pharyngitis?
Typically 1-2 weeks with antibiotic treatment, but may vary depending on individual circumstances.
Can someone have a recurrence of Streptococcal pharyngitis?
Yes, possible, especially if exposed to the bacteria again or if treatment is not completed as directed.
Article last updated on: 18th October 2025.
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