Poison Oak, Ivy, Sumac or what?

Last night i got on little teeny tiny bump on my leg, it was red and started to itch. Now it has spread a little bit in the area and also a little on my other leg. Now i have a bump on my arm that im trying to not scratch to avoid spreading. At the end of April, i had something similar. It started on my foot and eventually went all up my legs, on my fingers, the palm of my hands, my chest, elbows, and the bottom of my feet. That took about 3 weeks to clear up with the use of prescription ointment. I really want some opinions as to what it could be. It itches soooo bad! The bumps are fairly small, red, and in patches or lines. I should ad that i didnt get this until the the next day after i first started my new job at a mexican restaurant (started april 29, got it april 30) and once it cleared didnt come back until i went to work on sunday and it was there again that night. Could this have anything to do with it? Its a NICE mexican restaurant but its new, and just got a sanitation grade of C.