A sore throat often raises the question: Is this a regular cold or strep throat? Most sore throats are caused by viruses (viral pharyngitis) and do not require antibiotics. Strep throat (streptococcal pharyngitis) is a bacterial infection caused specifically by Group A Streptococcus (Streptococcus pyogenes). Distinguishing between these causes is important because only the bacterial infection requires specific medical intervention.
Relying solely on how the throat feels is unreliable, as both viral and bacterial infections can cause similar pain. Only a medical professional can definitively confirm the presence of S. pyogenes. This confirmation ensures proper treatment is administered, preventing unnecessary antibiotic use for viral infections and avoiding potential complications from untreated strep.
Key Differences in Symptom Presentation
Strep throat typically has a sudden onset, with severe throat pain often appearing overnight. This pain is usually accompanied by a fever of 100.4°F (38°C) or higher.
A viral sore throat, in contrast, develops more gradually over two to three days, often following other cold symptoms. One of the clearest distinguishing factors is the presence of upper respiratory symptoms like a cough, runny nose, or hoarseness, which are highly characteristic of a viral infection. These symptoms are rarely present with strep throat.
An examination of the mouth may show signs more common with a bacterial infection, such as red and swollen tonsils with white patches or streaks of pus. Some people with strep throat may also notice tiny red spots on the roof of the mouth, known as petechiae. Children are more likely to experience associated symptoms like a headache, body aches, or a stomach ache.
When Medical Intervention is Necessary
Any suspicion of strep throat should prompt a medical evaluation, especially in children between the ages of 5 and 15, as this age group is the most susceptible. Seeking care is also important if a person has had recent close contact with someone diagnosed with strep throat.
Immediate medical attention is necessary if symptoms progress to include difficulty breathing or swallowing, which can indicate severe throat swelling. A person should also consult a healthcare provider if a fever persists for more than two days or if the sore throat does not begin to improve within a few days of symptom onset. These signs suggest a possible bacterial cause or another complication requiring professional assessment.
The Clinical Testing Process
A medical professional confirms the diagnosis of strep throat through specific laboratory tests. The standard approach begins with a throat swab to collect a sample from the back of the throat and tonsils. This sample is then used for a Rapid Strep Test (RST), which provides results within minutes.
The RST works by detecting the presence of antigens from the Group A Streptococcus bacteria. A positive RST result is highly accurate, allowing for immediate treatment. However, the RST is less sensitive, meaning it may fail to detect the bacteria in some infected individuals, resulting in a false negative result in about 5% to 10% of cases.
When the RST is negative, but symptoms strongly suggest strep throat, a throat culture is typically performed as a backup. A throat culture is considered the definitive test, as it involves sending the swab to a lab to allow any bacteria present to grow over 24 to 48 hours. This longer process ensures the diagnosis is not missed, which is especially important for children and adolescents to prevent serious complications.
Treatment and Recovery for Strep Throat
Once a strep diagnosis is confirmed, treatment involves a 10-day course of antibiotics, usually penicillin or amoxicillin. Antibiotics are necessary to eliminate the Streptococcus pyogenes bacteria and prevent serious complications like rheumatic fever or kidney inflammation. It is important to complete the entire prescription even if symptoms improve quickly.
Most people begin to feel better within one to two days of starting the medication. A person is generally no longer contagious after taking the appropriate antibiotic for a minimum of 24 hours.
Patients are advised to remain home from work or school until they have passed this 24-hour mark and their fever has subsided. Supportive care, such as staying hydrated and using over-the-counter pain relievers, helps manage the remaining symptoms. Untreated strep throat can remain contagious for two to three weeks.