If you had chickenpox (varicella zoster) as a youngster, you probably remember it well.

The itching.

The scratching.

The perpetual discomfort bordering on pain.

What you probably don't remember, however, is being told by your parents and/or doctor that five, six or seven decades later the virus may just revisit you — in the form of shingles (herpes zoster).

ESPN broadcaster Keith Olbermann might be the latest baby boomer to be reminded — the hard way — that once the dreaded "zoster" comes to visit, it never leaves.

In February, the 55-year-old Olbermann missed a week of broadcasting of his eponymous nightly show after being felled by the burning, painful disorder.

His tweets — self-admitted "kvetches" — about the condition, though, were quite entertaining. Among them:

"It is mind-boggling to realize that I am dealing with a virus I contracted while JFK was still president"

"To those asking, Shingles [sic] feels like you fell 3 flights. Onto sharp poison ivy. Which then spontaneously combusts. Emitting toxic fumes."

"… Get the vaccine!"

Of course, for anyone who's suffered through a bout with shingles, they're no laughing matter.

What's more, a study of Medicare data published in December showed that, between 1992 and 2010, the annual rates of shingles cases in those older than 65 increased nearly 40 percent.

That same study concluded that for those who had chickenpox in their youth, between a quarter and a third eventually experience at least one episode with shingles.

The reason? Well, the medical community's guess is as good as yours or mine.

"Anything that is a 'stress' on the body could be a factor that contributes to a shingles outbreak," explains Dr. Thomas Balshi, owner and medical director of Balshi Dermatology and Cosmetic Surgery in Delray Beach, Fla. "Everything from the flu, arthritic injury and mental stress to too much sunlight or a sudden change in climate can do it. The list is endless. And, sometimes shingles erupts without any definable reason behind it."

The vaccine Olbermann referenced in his tweet — it's called Zostavax — is available to people 60 and older who've had chickenpox. The injection helps mitigate some of the risk for seniors, but it "doesn't provide 100 percent protection from getting shingles," Balshi said.

But, he adds, "Experts recommend that people older than 60 get this vaccine — whether or not they've had shingles before — because it considerably reduces the severity and risk of further complications of a shingles outbreak."

At the first sign of shingles — that is, when you begin experiencing nerve pain, burning or topical blistering — get to your doctor immediately.

"By taking antiviral prescription medication within 72 hours of an outbreak, you can help reduce the pain and duration of the disease," says Boca Raton, Fla., family physician Dr. Carlos Ballestas.

In severe cases, notes Ballestas, patients may need to supplement the antiviral meds with corticosteroids (to reduce swelling), antihistamines (to decrease itching) and Zostrix, a cream containing capsaicin, which helps control pain.

In addition, Ballestas warns that just because you've never had chickenpox does not mean shingles pose no threat.

"Exposure to shingles may cause chickenpox in adults or children who've never had chickenpox," he explains.

Guess that helps explain why Olbermann's signature signoff has always been: "Good night — and good luck."