The Threat to My Life

Water is evil discarnate, but over the years H2O and I have come to a tenuous agreement. I don't go near him, and he holds off on his homicidal tendancies. I'm not entirely sure what I've done to make him so angry, but my word has he tried to kill me an awful lot of times!
By the time I reached high school, I realized he was thristing for my blood and I'd so assiduously avoided any incarnation of him I scarcely showered. But junior year we went to Hawaii and when you're on a tropical island, you have to go in the water.
It was there and then that Senor Agua decided to pull his dirty trick. You see, I was very careful not to go too near the water or spend too much time in the water, so as not to give him the uperhand. He realized this and devised a way to make sure I was miserable even when I wasn't in the water.
All he had to do was get me wet and I'd break into this horribly read and painfully burning, itchy rash all over! The heavily touristed beaches have makeshift showers to wash the salt water off, but seculded beaches do not. So I sat there and burned and itched and everyone wondered why I was so allergic to paradise.
At first we thought it was just that one year. Perhaps some sort of odd weather event with a Spanish name (El Itcho?) had caused some strange microbes to churn up in the water. Plausible. But everytime I've returned to my island home, water still gives me a rash that threatens to eat me from the outside in.
And H2O likes to keep me on my toes. He likes sending reminders that even on dry land, a thousand miles away from the nearest ocean, he's watching and waiting. He'll send me a dream full of tidal waves larger and more ominous than anything reality can produce.
But although my life is in constant peril, I have my little revenges. I drink a glass of him and there's nothing he can do about it and after a while, I'll smirk and wave as I flush him down the toilet.