Cause
Tonsillitis is usually caused by a
virus. Bacteria can also cause tonsillitis. The most common bacterial cause of
tonsillitis is group A beta-hemolytic streptococcus (GABHS), which also causes
strep throat.
Tonsillitis can also be
caused by fungi or parasites, but these causes are rare in people who have
healthy
immune systems.
Although there is no
proof that exposure to cigarette smoke can cause tonsillitis, children who live
with a smoker have a higher incidence of tonsillectomy, which is a surgical
procedure to remove the tonsils.1
How tonsillitis is spread
Tonsillitis is spread by
close contact with an infected person. Droplets of disease-causing agents
(pathogens) pass through the air when an infected
person breathes, coughs, or sneezes. You may then become infected after
breathing in these droplets. Infection can also occur if pathogens get on the
skin or on objects that come in contact with your mouth, nose, eyes, or other
mucous membranes. Symptoms usually appear about 2 to 5 days after exposure.
A person with tonsillitis caused by strep bacteria is contagious
early on and without treatment can remain so for up to 2 weeks. Antibiotics
shorten the contagious period, and an infected person is no longer contagious
about 24 to 48 hours after beginning antibiotic therapy.