Most tonsil infections are called by tonsillitis. Tonsillitis is an
infection or inflammation of a tonsil. Sudden tonsillitis is often caused by a
streptococcus infection. It is marked by severe sore throat, fever, headache, malaise,
difficulty in swallowing, earache, and large, tender lymph nodes in the neck. Sudden
tonsillitis may go along with scarlet fever.