SUNDAY, Nov. 21, 2004 (HealthDayNews) -- Like the sequel to a bad movie, some medical conditions can show up years after an initial infection or injury. Many of them are every bit as bad -- or worse -- the second time around.
Take chickenpox, for example.
Once a common childhood illness that's now preventable by vaccination, chickenpox is characterized by an itchy, red rash that lasts 10 to 12 days, sometimes with a low-grade fever. But even when the itch passes and the rash fades, the chickenpox virus -- known as varicella-zoster -- has merely gone underground.
According to Dr. Bob Sears, a pediatrician in San Clemente, Calif., and co-author of The Baby Book, the chicken pox virus is very persistent. "It never completely leaves the body," he explained. "Varicella-zoster remains dormant in the nerves, and for most people, it is dormant forever."
"Forever dormant in most people" doesn't mean all people, however.
The varicella-zoster virus can come roaring back to life as shingles, also known as herpes zoster. According to the U.S. Centers for Disease Control and Prevention, approximately 300,000 cases of shingles occur in the United States each year. And this is not a pleasant condition.
Shingles is more common after age 50, and the risk increases with advancing years. The condition causes numbness, itching or severe pain followed by clusters of blister-like lesions in a strip-like pattern on one side of the body. The pain of shingles that can persist for weeks, months or years after the rash heals is known as post-herpetic neuralgia.
Shingles in and of itself isn't contagious, but you can get chicken pox if you've never had it. According to the U.S. Centers for Disease Control and Prevention: "People who have not had chickenpox can catch chickenpox if they have close contact with a person who has shingles. So, you get shingles from your own chickenpox virus, not from someone else." Theoretically, it's possible that you then could get shingles after you've had chicken pox.
Chickenpox isn't the only disease that has a nasty habit of coming back to haunt you. Mononucleosis -- or "mono" -- is another.
Mono is a fairly common acute illness in children and young adults caused by the Epstein-Barr virus (EBV), said Sears. EBV infection initially causes fever, a rash and sore throat, accompanied by fatigue that can last several months.
"Most people get over this illness," the pediatrician explained, "but some will go on to suffer from chronic fatigue syndrome, where the mononucleosis virus reactivates and causes fatigue, headaches and other general symptoms."
Then there's Bell's palsy, a usually temporary condition characterized by inflammation of one of the facial nerves resulting in weakened or paralyzed facial muscles on one side of the face, which can also result from EBV infection.
Other rare EBV-delayed effects include rupture of the spleen, inflammation of the heart muscle (myocarditis), involvement of the central nervous system (aseptic meningitis and encephalitis), and a nervous system disorder known as Guillain-Barr syndrome that can paralyze muscles.
And don't think viruses are the only culprits responsible for adult medical complications. Even relatively unspectacular childhood injuries can have significant later health consequences.
Dr. Andrew Iwach, an ophthalmologist on the clinical faculty at the University of California, San Francisco, said eye injuries that occurred decades earlier can manifest themselves in adulthood as serious visual disturbances.
"Blunt trauma injuries are the worst culprits," Iwach said. "Everyone expects there to be damage when a sharp object pokes a child in the eye. But what isn't so widely recognized is the longer term consequence of being whacked in the eye by something as relatively innocuous as a tennis ball."
Such an impact can set off a shock wave in the eye which results in a hyphema -- or bleeding in the anterior chamber, an area between the cornea and the iris. Hyphemas are bad enough the first time around but, according to Iwach, they are particularly vexing when the damage done in childhood re-emerges later in life and affects visual acuity.
"Whenever I see a patient who has one eye with an elevated level of intraocular pressure, I'm alert to the possibility that there was a history of blunt trauma to that eye," he said. "Sometimes that injury was many, many years in the past. And, often, the individual did not recognize the severity of the original blunt force trauma to the interior of the eye because the injury appeared to heal. But in actuality, these conditions can merely lie silent for a period, then re-emerge."
Iwach said the key to preventing permanent damage is to secure immediate diagnosis and treatment. "These injuries can't be ignored," he said. "If they are, they have a way of popping up in the future and affecting a person's ability to see."
More information
The U.S. Centers for Disease Control and Prevention has more information about chronic fatigue syndrome.
