ive been hospitalized for poison ivy more than once. you could say im highly allergic to it.
stay the fuck away from calamine, its only good for healing rashes. by rubbing the shit in you will make it much, much worse.
steriods are nice, but you dont need them unless you cant sleep form the itching...
what you need is a product called Technu. you can get it at most pharmacies.
technu is a bonding agent that traps/binds the oils that cause irritation from poison ivy/sumac/oak
you spray the stuff on, then take the hottest shower you can stand... never a bath. always showers.
they also make soap that has the same stuff in it, and even laundry soap to get the shit off your clothes and keep it from spreading to others in the household via the laundry.
its what the US foresty dept gives its rangers........ trust me on the shit, its the only thing ive ever used that actually works!!!!!!!!!!
and ps- the worst itching is when the rash is weeping.... dont scratch it, or rub the pus with your bare fingers, it will just keep spreading. when it weeps, blot the pus off your skin using a dry peice of tissue or toliet paper.... helps contain the rash very very quickly. keep the shit off your hands and clothes and it wont spread