My 4 year old son had Lyme Disease a few months ago. Playing around outside my in-laws house for a couple days, my wife found the tick during his shower. The tick must've been on him for a while because you have about a 0% chance of getting Lyme Disease unless the ticket has been attached for over 36 hours (see http://www.aldf.com/pdf/postersmall.pdf). We removed the tick and an expanding rash appeared on his back over the next few days. Could see it plain as day, grew to about 4 inches in diameter. Took him to urgent care (it was a weekend) and instantly diagnosed with Lyme. Important Note: Since the Lyme Disease test is an antibody test, it won't show positive for about 30 days after you're infected. A bulls eye rash over a certain diameter is clinically sufficient to diagnose Lyme. Another fun fact: once you test positive for Lyme, you will test positive for the rest of your life because your body retains the antibodies even though a previous infection is not protective of future infections.

He was on three weeks of antibiotics and the rash s-l-o-w-l-y disappeared over that time. He has no obvious ill effects thus far.