MADISON, Wis. -

Area doctors said a highly contagious virus is spreading through the Madison area at a strange time of year.

Hand, foot and mouth disease primarily affects children under age 5, and doctors at clinics around Madison say they have seen an uptick in cases the last few weeks.

Madison-Dane County Public Health officials said they don't track cases of the virus, but doctors have noted a larger number of calls, emails and visits resulting in the diagnosis of hand, foot and mouth disease, which can spread quickly among children.

Some area child care centers, as well as children's playgroups, have reported a number of cases popping up, and have even notified parents on Facebook pages or mandatory postings in day care centers of cases of the virus. It causes painful blisters on the hands and feet, as well as on faces and inside mouths. Children typically also have a fever for three to five days.

"I'm getting a lot of moms sending me MyChart messages and pictures of Johnny or Susie with funny fevers and rashes," said Dr. Danielle Gindlesberger, a Dean Clinic Family Medicine doctor at the Sun Prairie clinic. "We're answering a lot more questions about this kind of disease right now."

Officials at Dean Clinic said both their Sun Prairie and east side clinics have seen an uptick in cases. UW Health officials said they have also been seeing more cases in some of their locations.

Doctors say it is typical that the virus moves through child care centers but more often in the fall and winter. They say the strains are caused by four potential viruses, some of which can be more serious than others and can cause a child's fingernails to fall off weeks after the initial virus.

Doctors and the public health department encourage aggressive hand washing to try to prevent the spread.