By Stephanie Stahl

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PHILADELPHIA (CBS) — Lyme disease cases are up drastically in Pennsylvania, which now leads the country with the highest number of cases. Ticks are out now and will be through the summer and that has doctors renewing reminders to guard against tick bites, because Lyme disease can be serious.

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“There’s more Lyme disease in Pennsylvania, more cases of Lyme disease in Pennsylvania than in the next four states combined,” Dr. Anne Norris of Penn Medicine said.

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It’s been a year and Brian Dougherty still has some lingering effects of Lyme disease, including Bell’s palsy, which is partial facial paralysis.

Dougherty, who’s an ICU nurse in Philadelphia, also eventually developed heart palpitations, ringing in his ear and mental confusion.

He was chopping wood as a hobby and remembers finding a tick on his forearm.

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“It presented first like a fever and it went away, so I just thought it was a virus,” he said.

Lyme, caused by bites from certain kinds of ticks, can be hard to detect. There’s not always a signature bulls eye rash.

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“I’m very impressed with how sick Lyme disease can make people,” said Dr. Norris.

But Dr. Norris, with Penn’s Infectious Diseases Specialty Clinic, says 99 percent of Lyme cases are easily treated with antibiotics when it’s caught early.

Dougherty was eventually successfully treated with IV antibiotics.

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Dr. Norris says it’s critical for people in wooded or grassy areas to use insect repellent.

“We really need to up your tick bite prevention game,” she said.

What’s causing the big increase in Lyme cases in Pennsylvania is unknown as some speculate climate changes could be part of it.

And Dr. Norris says many people falsely think they have Lyme disease because the symptoms of fatigue and achiness are so common.

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For more information on Lyme disease, click here.

Stephanie Stahl