I’m sure Sinatra wasn’t thinking of ticks when he sang I’ve Got You Under My Skin. The song does express, however, how a host’s body reacts to their bite.
Barbed mouth parts to get a strong hold
You probably know the first action you need to take if you see an attached tick is to remove it quickly. If you’ve ever tried removing a tick, you know how difficult that can be. Ticks do get under their host’s skin and attach very firmly. A deer tick’s mouthparts include barbed chelicerae similar to barbed teeth. Inside the chelicerae is a hypostome or tube like structure. The chelicerae penetrate the skin and the barbs push laterally in a clawing action to anchor the tick firmly. (National Geographic has a video of the beginning of this process). In hard ticks, like deer ticks, saliva is produced. The saliva quickly produces a protein that forms a cement-like substance around the hypostome to lock it in place.
Helping blood pool under your skin makes it easier to drink
While the tick is biting and attaching itself under the skin, their saliva ensures the host’s immune system will go along and ask, “why should I try to resist, when baby I know so well that I’ve got them under our skin”. Tick saliva produces numerous molecules not yet studied by science. The molecules accomplish several tasks. We know one thing they do is reduce inflammation around the bite. A tick bite breaks small blood vessels under the skin so that blood will pool, making it easier drink. By reducing inflammation, blood platelets will not assist the blood in clotting so the host’s blood will flow freely to the tick. Reducing inflammation also prevents the skin from itching and allowing the host to know they’ve bitten.
How they hold off our infection long enough to finish their job
Finally, the tick needs to protect itself from the host’s immune system and additional molecules in the tick’s saliva accomplish this function. These molecules allow the tick to ingest a host’s blood while being protected from white blood cells of the host that fight the tick’s infection.
Lyme Disease bacteria are found in a tick’s saliva and stomach, so proper removal is important. Improperly removing ticks will cause more saliva to be released and their stomach contents to be regurgitated into the bite. Research shows that ticks removed within 24-36 hours of being attached have little chance of transmitting Lyme Disease. The CDC has a webpage designed to show how to remove ticks from the skin. Unlike the lines in Sinatra’s signature song, do resist ticks when you’ve “got (them) under your skin”.