Tough strain of hand, foot, mouth disease hits
MEDICINE But no increased danger from hand, foot and mouth disease
Published 4:00 am, Tuesday, April 17, 2012
A new strain of hand, foot and mouth disease is circulating in the Bay Area, and is causing more severe and sometimes alarming symptoms than the display of minor rashes on feet and hands, and in the mouth, typically associated with the common childhood infection.
The new strain does not seem to be more dangerous than the traditional disease, but it has caught the attention of pediatricians and epidemiologists who are intrigued by the changing symptoms. They are seeing patients who have a much more widespread rash and, weeks after the infection has cleared, the loss of finger- and toenails.
"We don't see reports of kids dying or being injured by this disease. But it's not quite as benign as regular hand, foot and mouth disease," said Dr. Dan Kelly, a San Francisco pediatrician. "It's worth parents being aware of. People will worry if their kids' fingernails fall out."
Reports of the new illness are coming mostly from pediatricians who have treated patients with rashes that didn't fit the normal hand, foot and mouth description. Outbreaks of the illness have occurred at Bay Area schools and day care centers in recent months. It's not clear that those cases involve the new strain, but the timing of the outbreaks is unusual because the illness normally hits in the late summer and fall.
Hand, foot and mouth disease is well-known among parents as a common cause of a pimply rash on the feet and hands of their children, along with painful sores in the mouth. The rash usually fades after a few days, and the most common complication is dehydration, from kids not wanting to drink anything due to the sore throat.
Spreading the illness
The illness is spread the same way the common cold is - through sneezing, coughing and touching surfaces with infected hands, and contact with feces or with fluids that may be discharged from the rash.
The new illness seems to cause a much larger and more profound rash - it can spread up the arms and legs, across the buttocks and torso and onto the face. In both the old and new strains, many patients get a fever that lasts a day or two. The new strain, however, seems much more likely to cause nail loss than the traditional one - Kelly said that of the 10 patients he's seen so far, four have lost at least part of their nails.
It's rare for adults to get hand, foot and mouth disease, but they seem more likely to get the new strain than the old one. One U.S. report found that a quarter of cases of the new disease involved adults.
The new strain was identified late last year, when a Bay Area pediatrician found a large, worrisome rash on a patient and reported it to state epidemiologists in Richmond. The epidemiologists immediately ruled out smallpox - the first major concern with a mysterious rash - and then set about trying to identify the disease.
They initially thought it was a herpes infection, said Dr. Carol Glaser, chief of the California Department of Public Health's encephalitis and special investigations section who works out of the Richmond lab.
"I was thinking disseminated herpes virus, or a really severe chicken pox, and then I thought about some more exotic viruses such as monkeypox," Glaser said. "We went through a lot of different things, but (hand, foot and mouth) was not on my list."
Investigators eventually tested a sample for the viruses related to hand, foot and mouth, and came up with the coxsackievirus A6 (CVA6), which began showing up a couple of years ago from Europe and Asia. Hand, foot and mouth is usually caused by a similar virus called coxsackievirus A16.
Glaser sent her report to the U.S. Centers for Disease Control and Prevention. Investigators who saw photos of the rash at the CDC said, "Wow, that is striking. We haven't seen anything like it," Glaser said.
But a few weeks later, the CDC had reports of cases in Alabama. Now the strain has been found in at least four states, according to a CDC study released late last month that Glaser contributed to. That report identified 63 patients who likely were infected with the new strain.
But both Kelly and Glaser think the disease is much more widespread. California, for example, only has seven cases listed in that report, but Kelly's office alone has seen at least 10 patients who almost definitely have the new strain.
"The (California) reports have been pretty much limited to the Bay Area. I suspect it's in Central and Southern California, too, and it's either not being recognized or not being reported," Glaser said.
Tamping down worry
Hand, foot and mouth disease isn't monitored by state or local public health authorities because it doesn't usually cause severe illness. But Glaser said that given the superficial severity of the symptoms, it's worth alerting pediatricians and parents to the new strain, if only to keep them from worrying too much.
In addition, there have been a handful of reports, both in the United States and overseas, of patients who needed to be hospitalized because of complications from the new strain. It's very rare for a child to be hospitalized with the old strain, Glaser noted.
Kelly said parents should be on the lookout for a fever that lasts more than a few days or symptoms like vomiting and lethargy that grow worse over time. Treatment with over-the-counter pain relievers is the same for both the new strain and the traditional one, and the rash almost always disappears on its own after four or five days.
On the whole, the illness is something parents should be aware of - but not overly worried about, said Dr. Ken Purdy, a pediatric infectious disease expert with Kaiser Santa Clara.
"It can alarm parents, because it looks kind of like chicken pox to a lot of people," Purdy said. "But the big message I tell parents is these infections don't generally last more than a week. And you should wash your hands pretty well if you have a family member with it."
Hand, foot and mouth disease
Hand, foot and mouth disease is a common childhood viral infection. A new strain of the disease that causes more severe symptoms is circulating in the Bay Area. The differences in symptoms include:
A larger, more widespread rash: In traditional hand, foot and mouth disease, the rash is made up of tiny, pimple-like spots on the hands and feet and in the mouth. With the new strain, the rash can spread up the arms and legs, across the torso and buttocks and onto the face. The pimple-like spots are also larger and can be connected, forming larger, fleshier lesions.
Loss of fingernails and toenails: Patients with the traditional disease occasionally lose nails, but nail loss appears to be more common in the new strain. Patients start to lose their nails about four to eight weeks after the infection has passed.
Adult infections: People over age 18 rarely get hand, foot and mouth disease, but some adults seem to be vulnerable to the new one.
Possible hospitalizations: Public health officials in the United States and abroad have reported a handful of hospitalizations from the new strain of hand, foot and mouth disease, but doctors say the illness seems to be minor for most people.
How it's spread: In both strains of the disease, the virus can be spread the same way as the common cold - through sneezing, coughing and touching surfaces with infected hands, and by contact with fluids that may be discharged from the rash.
Preventive measures: Parents and other adults who work with children should wash their hands regularly and thoroughly, and disinfect toys and other surfaces children have touched.
Erin Allday is a San Francisco Chronicle staff writer. email@example.com