Pharyngitis, commonly known as a sore throat, is an inflammation of the pharynx, which is in the back of the throat. It is usually caused by viral and/or bacterial infections, such as the common cold and flu (both viral infections) or by infection with the Streptococcus bacterium (strep throat) . Other less common causes of pharyngitis include allergies, trauma, cancer, reflux, and certain toxins. Fungal pharyngitis occurs in the setting of immunosuppression or chronic steroid and antibiotic use. Sometimes, allergies, such as hay fever or allergic rhinitis, can cause a sore throat. Dry indoor air and chronic mouth breathing, especially in the winter, can lead to recurrent sore throat, particularly in the morning, after waking up. Muscle strain associated with voice use can cause a pain in the throat that is similar to pharyngitis. Gastroesophageal reflux disease (GERD) can lead to chronic sore throat because of stomach acid reflux irritating the throat.

The symptoms of pharyngitis include a sore throat, dry, scratchy throat, pain when swallowing, and pain when speaking. Other symptoms may be present, depending on the cause. These include fatigue, malaise, muscle aches, headache, and fever, especially with the flu or other viral infections.

Pharyngitis is diagnosed through a physical exam and may require additional tests, such as a throat culture or rapid strep test, to determine the cause of the sore throat. Treatment for pharyngitis depends on the underlying cause. Most cases of viral pharyngitis are self-limited and do not require treatment. Bacterial infections require antibiotics. The most common bacterial infection of the throat is strep throat, which is caused by group A streptococcus. Rare causes of bacterial pharyngitis include gonorrhea, chlamydia, and corynebacterium[[6...