With a tick-bite reaction, the red area does not expand over 24 to 48 hours. Small reactions at the bite site can last days to weeks. The earliest stage of Lyme disease occurs at the site of the tick bite. If the rash is Lyme, it will get bigger over days or weeks and will not fade over the next few days.Only 2% of tick bites result in Lyme disease. A Lyme rash occurs at the site of the tick bite in 80% of people who have early Lyme disease.The incubation period from a tick bite to the development of a rash is 3-30 days (usually 3-10 days).f the rash is Lyme, it will get bigger over days or weeks and will not fade over the next few days. Only 2% of tick bites result in Lyme disease. A Lyme rash occurs at the site of the tick bite in 80% of people who have early Lyme disease.