Rash after being in Lake Washington.

I was at Madison Beach yesterday.

I noticed this rash as soon as I got out the water.

Got worse when I got home.

I know its not a heat rash as I was shirtless and working in the yard all morning and afternoon. Rash was not there.

I also do not have sensitive skin, as I spend a lot of time outside, and work in Healthcare so exposed to a lot of pathogens.

This was just very bizarre. Is this something that should get reported to a city department?