Pharyngitis can be acute or chronic inflammation.  Commonly among adults who live or work in dusty or very dry environments, use their voices excessively, use tobacco or alcohol habitually, or suffer from chronic sinusitis, persistent coughs, or allergies.
Acute pharyngitis may precede the common cold or other communicable diseases.  Chronic pharyngitis is commonly an extension of nasopharyngeal obstruction or inflammation.  Uncomplicated pharyngitis usually subsides in 3 to 10 days.

Cause;  In children, it is often caused by streptococcal bacteria.  In 90% of cases, pharyngitis occurs as the result of a virus.

Symptoms:

Sore throat
Difficulty swallowing (swallowing saliva is usually more painful than swallowing food)
Sensation of a lump in the throat
Have the urge to swallow constantly
Redden, inflamed posterior pharyngeal wall
Mild fever
Headache
Muscle and joint pain - especially in bacterial pharyngitis

Treatment:

Treatment is usually symptomatic - consisting mainly of rest, warm saline gargles, throat lozenges containing a mild anesthetic, plenty of fluids, and analgesics as prescribed by your doctor.

Bacterial pharyngitis requires antibiotic therapy - usually penicillin or another broad spectrum antibiotic if the patients is allergic to penicillin.