I am very grateful for all the advice you have provided. This duck itch is really miserable. I know, because now I have it, too!
It looks like the chicken pox and the itching is non-stop. But we don't want it to ruin summer fun on this awesome lake (that is, if the sun would ever shine again.) So from now on we shall heed all of the precautions you have posted. Again, many thanks to everyone.