Words that make you feel things

What is it about words like LICE, CHICKEN POX and SCABIES, that make us involuntarlily itch? Ugh, I just starting itching thinking about it. After being a nurse for 4 years, I had my first patient with Scabies. Ugh! Despite my best efforts to channel my thoughts and not think about being gloved, gowned, bouffant capped and masked, I envisioned them jumping onto my pant legs (the only thing not covered). After I left for the night, I had an uncontrollable itch all of the way home. Unfortunately the drive was about 45 minutes long! I am not a germaphobe like many of my other co-workers. I actually feel like some germs are good for us and build up our immune system. Unfortunately scabies isn't one of them, I stripped down as soon as I got home, refused to pet my overly excited animals and got into the shower! Even afterward...I still had the itchies. Somedays, I feel like I have the grossest job. Despite all of that, I still love it.