Herpangina is caused by a virus known as the "Coxsackie virus", because it
was first found in patients in the town of Coxsackie in eastern New York.
(There are actually many different types of Coxsackie virus which cause
several different diseases; herpangina is caused by only one or two of these
"serotypes".) The virus is classified as an "enterovirus", which means
that it is most often found in the gastrointestinal tract, and although
enteroviruses are commonly responsible for
gastroenteritis ("stomach
flu"), they can cause many other diseases as well, including
fever without other
symptoms. There are tests to see if you are infected with the virus,
but they rely on the immunity you develop to the virus and so take
several weeks to run, and these tests are available mainly in
research laboratories.
The herpangina virus can be spread by saliva and mouth-to-mouth
contact, as well as by contact with an infected person's stools. It
usually takes 3-6 days after exposure to become infected. We tend to see
more cases of herpangina in the summer; the rise in herpangina cases
we see each summer seems to be related to the weather.
Typically a person with herpangina has a fever and a very sore throat, and possibly a sore mouth as well. If you look inside the mouth, you will most likely see a very red throat at the back and a very red area at the back of the roof of the mouth, with several small (1-2 mm in diameter) blisters that look just like canker sores. This is a picture of a true canker sore (more properly, an aphthous ulcer); note that the entire sore is raised a bit and that the red rim is slightly raised even above the surface of the ulcer.
The lesions of herpangina are caused by the virus, unlike true canker
sores. However they behave just like canker sores: they hurt a great
deal, especially when you try to eat or drink anything that is salty,
spicy, or acid (like orange juice or lemonade). Milk seems to be fairly
soothing for some patients. Often a child with herpangina will be able
to drink without discomfort but can't eat solid foods because of pain
(from salt or acid in the food, or just because the solid or
partially-chewed food scrapes against the sores).
In more severe infections, there are more sores in the mouth -- inside the
lips and on the inside of the cheeks, as well as in the throat. We can
also see blisters around the outside of the mouth, and in the full-blown
infection we find painful blisters on the palms and on the soles of the
feet (hence the name "hand, foot, and mouth disease).
The pain and fever will make you quite uncomfortable while you have the
sores. The biggest problem with herpangina, though, is that the pain
may make it difficult for you to drink enough to avoid becoming
dehydrated.
(Unlike stomach flu,
you become dehydrated with herpangina because it hurts so much to drink.)
I have seen people with herpangina (including a fellow former resident
doctor) who needed IV fluids because they couldn't drink enough. Although
you get dehydrated in a different way, though, the
signs of
dehydration are the same, and you should watch for these.
Unfortunately, since it is caused by a virus, there is no medicine that will make the infection itself go away -- you have to wait for your body's immune system to get rid of the virus. In some cases, however, there are medicines we can give to soothe the pain. Acetaminophen, ibuprofen, and other over-the-counter pain medicines can be helpful. There are also some prescription medicines that can be swished around the mouth to help soothe the pain enough for you to drink and maybe even to eat. (There are particular combinations of medicines that I and other doctors I know use on ordinary canker sores that also seems to help a lot with herpangina pain. You need to ask your doctor about these medications, as they may be harmful if used improperly. If you are a physician, I will be happy to give you the details by E-mail.)