Hi Vick -
There are a number of things which can cause a rash beyond just poison ivy / urushiol oil. In water, there is a parasite which causes a rash known as "swimmer's itch". Swimmer's itch is an allergic reaction - here's some great information Cercarial dermatitis. Given that you were in a stream the sheer volume of water would negate the possibility that urushiol oil in the stream was the cause of your rash.
As for your second question - it is possible and even likely that with each successive contact with urushiol oil the rash will be worse. This comes with a caveat though. The T-cell memory is finite meaning if there is a period of time (perhaps years) between contacts the rash will actually be less or non-existent.
Oh and one last thing I just noticed in your message. It is possible that in a freshly mowed field you came across poison ivy. The plant will grown amongst grass, brush, trees, etc. In the case of the mowing, there would be little bits of poison ivy plant over the area where it had been. |
