As Jerry noted above: “It seems like I’ve gotten more reactive. If the tick is embedded for more than a day, the area will swell up. I took antihistamine.”
From personal experience it is a reaction to the bite which becomes more intense depending (evidently) on the amount of time the tick spent at that location as well as the number of times your immune system has experienced this type of “invasion” and how rapidly and strongly it has learned to respond. Ticks can bite (drilling for blood!) in several places as they look (again evidently) for a juicy vein or artery. There’s probably more fluid exchange involved with more thorough and lasting attachment. (strike/gusher!)
I evidently have a very well trained immune response to this type of invasion.
The problem occurs when you begin to exchange blood as I understand it and this takes @ a day.
In my case the itchy welt from a firm attachment can last nearly a month. Lots of cortaid! Though can’t remember the last time I had a tick that was apparently beginning to extract blood. Thorough checks!
Ken’s summary bears repeating: “Moral of the story? I now treat my shoes, socks, and pants with Pemethrin each spring and haven’t had a tick on me since. It’s just not worth it!”
Speaking of “worth it”: The variety and hazard of disease spread by ticks goes well beyond Lymes and several can be potentially spread by the same tick/bite/exchange. Also more are apparently being discovered. There is also pretty strong evidence that lymes can be, well; complicated and in some cases for some reasons evidently not well understood extremely difficult to cure along the complicated lines of long covid, malaria, syphillus or other complicated or evasive disease that can remain dormant, hide somehow at the cellular level and evade treatment for long time periods; like years and years or maybe the rest of your life. Also the disease is being spread among populations of hosts like deer mice and rabbits and warming climate is resulting in the spread of  the range and prevalence of certain ticks as well as the extent of seasonal activity. BOTH!
This article will get your attention! I think you can avoid the paywall or it doesn’t block your reading one article. LYME DISEASE IS BAFFLING, EVEN TO EXPERTS
Hmmm just occurred to me. Wonder if you can buy stock in Sawyers?
Edited to add: Now that I think about it and especially relative to BPL the growing range and extended seasonal problem has an added dimension which is elevation. 4500′ used to be safe in the Southern Appalachians? Make that 5000′. That sort of calculation.
And one more thing. Whoever upthread mentioned that ticks attach to vegetation had it right but wait there’s more! They are a member of the spider family and have 8 legs. Arachnophobia! They will hang on grasses or brush along game routes with the back pair or pairs and when they feel the vibration of something treading forward wave the front pairs to catch the passing creature. They are very good at it. Some have postulated they might also ‘parachute’. I’ve had cases that would seem to support this but it would be an interesting trial to try and scientifically verify. Also they detect and move towards carbon dioxide from exhalation. Co2 is often used by field researchers to attract ticks. And speaking of Arachnophobia some of us also have to deal with their little cousins who evidently do not spread disease but only misery; the red-bug or chigger. Another topic but permethrin also works!
Lastly: The Life Cycle of Ticks