When you get pesticides on your skin it can sometimes cause skin irritation or a chemical burn or rash if not washed off in time.
When using pesticides you should always wear some long rubber gloves that cover both your hands and arms as well.
If you do happen to get pesticides onto your skin then you should immediately or soon after wash the pesticides off your skin with some soap.
You may have to wash your skin a few more times to remove the pesticides from your skin entirely but usually not much will happen as long as you wash your skin off soon after you get the pesticides from your skin.
I've gotten pesticides onto my skin before and nothing happened except for a little itching but I washed the pesticides off within a few minutes of coming into contact with the pesticides.