The practice of purposely infecting kids with the chickenpox virus — in an effort to "get it over with" — worries doctors for many reasons.

You're invited ... to a chickenpox party. Huh? Years ago, it wasn't uncommon for parents to bring their kids over to a friend's or neighbor's house when a child turned up with the classic itchy, red, blistery rash of chickenpox, a disease caused by the varicella zoster virus.

Since the virus is extremely contagious — it can be spread when an infected person coughs or sneezes, or through touching the fluid from chickenpox blisters — exposing your child to a pal with pox was often enough to have him catch the disease. And since most kids would get it anyway — before a vaccine was introduced in 1995, 90% got chickenpox before the age of 20 — parents figured why not catch it and get it over with? Plus, the disease can be more serious in teens and adults than in children, so having it in childhood and developing an immunity to prevent him from getting it later was another incentive.

"You definitely want to be immune to chickenpox before you become an adult, when it's much worse, so parties were a good idea before the vaccine was introduced," says Rodney E. Willoughby, M.D., a pediatric infectious disease specialist at Children's Hospital of Wisconsin, professor of pediatrics at the Medical College of Wisconsin, and a member of the AAP's committee on infectious disease.

Today, it's a bad idea, yet in our era of social media, it's not unheard of to see a "pox playdate" posted online welcoming parents to bring their little ones to a home where a child has the chickenpox. In Boulder, Colorado, parents who fear there could be dangerous side effects of the chickenpox vaccine are even organizing “pox parties” in private Facebook groups.

But unlike the Internet and Facebook, we have something now that didn't exist years ago — a safe, effective vaccine for chickenpox. Which means an invite to a chickenpox get-together is now an invitation you should definitely turn down according to the experts.

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Why You Should Say No to Chickenpox Parties

Simply put, there are zero pros to taking your child to a chickenpox party because you don't want your child to get chickenpox. Though it's usually not dangerous in most kids, the virus does bring with it the potential for serious complications including pneumonia, bleeding problems, encephalitis (brain swelling), bacterial skin infections, toxic shock syndrome, bone and joint infections, and even death.

Even otherwise healthy kids can suffer dangerous, even life-threatening, complications from chickenpox, and there's no way to predict whether your child will be one of the ones who does. In contrast, "the virus in the vaccine has about a one thousand-fold less chance of serious rare complications than wild chickenpox" — the virus you can catch — "and close to zero risk of a fatal complication," says Dr. Willoughby.

Even if your child isn't among those who end up with complications from chickenpox, living through the disease itself is no fun. It can be extremely uncomfortable and keep your child out of school or childcare (and you out of work) for more than a week.

"If your child can get a vaccine so he'll never get pox and aren't out of school for 10 days, then why do a chickenpox party? You can schedule a shot for one day, instead of dealing with sickness for ten days," says Dr. Willoughby. "You get the same immune protection with much less suffering. What's not to like?"

More Chickenpox Warnings from Experts

It's possible to purchase an item online — often a lollipop — purported to contain the chickenpox virus. The idea: have your child lick the used lollipop so she can get chickenpox "naturally." Not only is that gross, it can be downright dangerous.

"It blows my mind that people are doing this because we have a very safe vaccine against chickenpox," says Mary Anne Jackson, M.D., division director, infectious disease at Children's Mercy Hospitals and Clinics in Kansas City, Missouri, and member of the American Academy of Pediatrics' (AAP) committee on infectious disease. "By doing this, you're going to unintentionally transmit other things like hepatitis B and group A strep. Not to mention that it's illegal to send any virus by mail."