urushiol rashes. they ain't spreadin'

the itching started on my wrist. so i scratched. two days later, my neck displayed a red rash and i scratched again. a day after that, my chest was on fire. of course, i scratched.

i am fearful that by scratching the original rash on my arm, i caused it to spread (via the transfer of oils) to my neck and chest. but if this was the case, why isn't my entire body covered in itchy rashes - because i am sure that my neck and chest are not the only places that were touched after my intense arm-scratching episodes.
my hunch is that the rashes on the neck and chest were delayed...possibly by a traffic jam in the conduit for IgE cells?!

after a quick wikipedia search, i believe urushiol oil is to blame for the rash. both poison ivy and mango peels contain this oil. both, i have been in contact with in the past week. i am therefore diagnosing myself with a 'urushiol induced contact dermatitis'. and i believe, according to wikipedia, that this kind of rash can appear over a period of time. therefore, it can be concluded that all itchy/rashy areas of my body had simultaneous oil exposure, and it took a while for my immune system to react everywhere needed.

satisfyingly, it seems i can scratch til the cows come home, because this rash ain't spreadin' nowhere.