Stains on hands

My 19 month old son and I both woke up with these strange stains on our hands.  It looks like iodine or betadine.  I have it on the meaty part of the base of my thumb and on my right hand fingers.  My son has it all over both hands and he has some strange shapes on his right thigh.  We both scrubbed up in the shower this morning and it will not come off.  It did not have a smell too it an there is nothing him or I could have both gotten in to in the middle of the night.  There is nothing on either of our sheets or pillow cases.  And there was nothing on our pajamas.  I am confused and wonder if anyone can help us out???  It looks like a botched sunless tanning job only I have never had that stuff in the house.  I was in my bed all night so i know I didnt get into anything and I don't sleepwalk??????