A sore throat can signal a mild viral infection like a cold, caused by viruses such as rhinoviruses, or a more concerning bacterial infection such as strep throat. The common cold typically resolves without specific medical intervention. Strep throat, however, is caused by the bacterium Group A Streptococcus (GAS), and it requires antibiotic treatment. Differentiating between the two is important because untreated strep throat can lead to serious complications like rheumatic fever or kidney inflammation. Prescribing unnecessary antibiotics for a cold also contributes to antibiotic resistance.
Symptom Comparison
The way symptoms begin can offer the first clue, as a cold usually has a gradual onset, with symptoms slowly worsening over several days. Strep throat, in contrast, tends to strike suddenly, often with an intense sore throat that develops rapidly.
The throat pain associated with strep is typically severe, especially when swallowing, and is frequently accompanied by a fever of 101°F or higher. A physical examination may reveal red and swollen tonsils, often with white patches, streaks of pus, or tiny red spots on the roof of the mouth, known as petechiae. Children with strep may also experience abdominal pain, nausea, vomiting, or a fine, sandpaper-like rash, which is a sign of scarlet fever.
Upper respiratory symptoms strongly suggest a viral cold. Cold indicators include a runny nose, nasal congestion, sneezing, and a cough. Strep throat usually occurs without these symptoms, making the severe sore throat and fever the predominant issues. A sore throat due to a cold is often mild and secondary to other symptoms, while a strep sore throat is usually the most prominent and debilitating symptom.
Medical Testing for Confirmation
Because symptoms alone can be misleading, medical testing is often necessary to confirm the cause of the illness. It is advisable to seek medical attention if a severe sore throat persists, if a high fever lasts more than 48 hours, or if classic strep indicators like pus on the tonsils are present.
The most common diagnostic tool is the Rapid Strep Test (RST), which involves quickly swabbing the back of the throat to check for Group A Streptococcus bacteria. The RST provides results within minutes, allowing for a fast diagnosis and immediate treatment if the result is positive. While a positive RST is highly reliable, the test is not always sensitive enough to detect all infections, leading to the possibility of a false negative result in about 5–15% of cases.
If the RST is negative but clinical suspicion for strep throat remains high, a throat culture may be performed. The throat culture is considered the gold standard because it allows the collected sample to grow in a lab, which can detect smaller amounts of bacteria. The drawback is that results take longer, typically 24 to 48 hours, but it provides a more definitive answer.
Treatment and Recovery
Once a diagnosis is confirmed, the treatment paths diverge completely. Since the common cold is viral, antibiotics are ineffective. Cold treatment focuses on supportive care to manage symptoms until the illness runs its course.
This care includes getting plenty of rest, staying well-hydrated with fluids like water and clear broths, and using over-the-counter medications for pain and fever relief. Symptoms of a cold generally last for seven to ten days, although a lingering cough or congestion can persist longer.
Strep throat, being a bacterial infection, requires a full course of antibiotics, typically penicillin or amoxicillin. Patients usually begin to feel better within 24 to 48 hours, with significant improvement seen within three to seven days. It is important to complete the entire course as prescribed, even after symptoms improve, to fully eliminate the bacteria and prevent potential complications. A person is generally no longer contagious and can return to work or school after being fever-free for at least 24 hours and having taken antibiotics for a full day.