Diphtheria is a disease seen infrequently in the United States.
It is caused by infection with the bacterium Corynebacterium diphtheriae. Three-fourths of all cases occur in children. The disease begins suddenly with fever, malaise, and sore throat. A characteristic feature is a thick, gray tonsillar exudate is present and may spread rapidly to cover the tissues of the throat around the tonsils, the uvula, soft palate, rear wall of the throat, and the larynx. The exudate is tenacious and not easily removed.