Mononucleosis, or mono, takes weeks to show up—and weeks to go away. But it’s not as scary as it seems.

Several viruses can cause mono, but the Epstein-Barr virus (EBV) is the most common. The illness looks a lot like strep throat. Babies and very young children can get EBV, but they don’t always show symptoms. Teenagers and young adults are the people most likely to get sick.

“It’s really in teens that we see classic mono—sore throat, fever, tiredness and swollen tonsils,” says Rachel Orscheln, MD, a Washington University infectious diseases physician at St. Louis Children’s Hospital. “Symptoms can show up anywhere from four to six weeks after a teenager gets exposed to the virus.”

How to Heal

There’s no cure or treatment for mono. Instead, doctors tell parents to make sure a child drinks plenty of fluids and gets a lot of rest. Over-the-counter medicine can be used to help sore throats and fever.

“Some people with mono can have a swollen spleen or liver,” Dr. Orscheln says. “When that happens, these organs can rupture. To keep that from happening, we suggest kids who get mono stay out of contact sports until their doctor says it’s OK to start playing again.”

Another long-lasting issue is fatigue, or feeling very tired. Some children or teens feel more tired than usual for a few months after all their other symptoms are gone. Mono can also lead to other serious infections and inflammation of the brain and heart muscle. But these problems are very rare, according to Dr. Orscheln.

“Mono is a common illness,” Dr. Orscheln says. “Although it can cause a lot of symptoms, most people will recover in a few weeks.”

If your child has symptoms of mono, call a pediatrician. Need one? Call St. Louis Children’s Hospital at 314.454.KIDS (5437) or toll-free at 800.678.KIDS.


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