Whether antibiotics are needed for a sore throat depends entirely on its cause. Strep throat is a specific infection caused by the bacterium Streptococcus pyogenes, commonly known as Group A Streptococcus (GAS). This bacterial infection must be distinguished from the far more common viral sore throat, as only the bacterial form responds to antibiotics. Since the vast majority of sore throats are caused by viruses, a definitive diagnosis is the only way to determine if antibiotic treatment is appropriate. Antibiotics are mandatory only when strep is confirmed, primarily to prevent serious, long-term complications that can affect the heart and kidneys.
Distinguishing Strep from Viral Sore Throats
Most cases of pharyngitis, or sore throat, are caused by viruses, such as those responsible for the common cold or flu. Viral sore throats often present with upper respiratory symptoms like a cough, runny nose, or congestion, which are rarely seen with strep throat. Strep throat typically has a sudden onset, characterized by fever, pain when swallowing, and visibly swollen tonsils that may have white patches of pus.
Because symptoms alone are unreliable for diagnosis, healthcare providers use specific tests to confirm the presence of Group A Streptococcus. The most common method is the rapid strep test, which involves swabbing the throat to detect bacterial antigens quickly. If the rapid test is negative, a throat culture may still be performed, especially in children, as it is a more sensitive test that takes 24 to 48 hours for results.
Clinical signs, such as the absence of a cough and the presence of swollen neck lymph nodes or tonsillar exudate, help providers decide whether to test. For children aged 5 to 15, who are the most susceptible, diagnosis is confirmed by a positive test result, which then mandates treatment.
Mandatory Treatment: Preventing Serious Complications
Once a strep infection is confirmed by a lab test, antibiotic treatment is necessary, not primarily for symptom relief, but to prevent severe, non-suppurative complications. The main purpose of the 10-day antibiotic regimen, typically penicillin or amoxicillin, is to quickly eradicate the bacteria. This timely eradication interrupts the immune response that can lead to long-term health issues.
The most concerning complication is Acute Rheumatic Fever (ARF), an inflammatory disease that can occur two to three weeks after an untreated strep infection. ARF can cause permanent damage to the heart valves, known as rheumatic heart disease. Antibiotic therapy is highly effective at preventing ARF, even when started as late as nine days after the initial symptom onset.
Another serious consequence is Post-Streptococcal Glomerulonephritis, which involves inflammation of the small filters in the kidneys. This complication presents as kidney damage and usually appears one to three weeks following strep throat. While antibiotics do not reliably prevent this kidney condition, they are still administered to reduce the risk of ARF and limit the spread of the bacteria. The prompt administration of antibiotics, therefore, acts as a public health measure to limit transmission.
Understanding Antibiotic Use and Resistance
For the majority of sore throats that are viral, antibiotics should not be used because they are completely ineffective against viruses. Prescribing an antibiotic for a viral illness does not speed up recovery and only exposes the patient to unnecessary risks. These risks include common side effects like diarrhea, nausea, and allergic reactions, which can range from mild rashes to severe anaphylaxis.
A greater concern is the contribution of this misuse to the global problem of antibiotic resistance. When antibiotics are used unnecessarily, they kill off beneficial bacteria in the body, allowing resistant strains to survive and multiply. This practice diminishes the effectiveness of these medications against actual bacterial threats, making future infections much harder to treat.
Healthcare professionals must practice antibiotic stewardship, prescribing these medications only when a bacterial infection is confirmed. If a sore throat test is negative for Group A Streptococcus, the appropriate action is to manage symptoms with pain relievers and throat lozenges, allowing the immune system to clear the viral infection.