Acute epiglottitis: A rapidly progressive infection causing inflammation of the epiglottis (the flap that covers the trachea) and tissues around the epiglottis that may lead to abrupt blockage of the upper airway and death. The infection is usually caused by bacteria. The inflamed epiglottis mechanically obstructs the airway and impairs the breathing process.
The onset of epiglottitis is generally rather sudden. Sore throat and hoarseness, frequently with a high fever, develop abruptly in a previously well individual. Trouble swallowing and respiratory distress with drooling, difficulty breathing, fast breathing, and noisy inspiration develop rapidly, often causing the person to lean forward and hyperextend the neck to enhance air exchange.