Baby with a werid fungus like rash on skin???

My 6 month old baby has a werid rash that are spots on his arm and butt, they are red and the outer line and blueish in the middle, they kind of look like brusies.. my baby's doctor told me that it was fungus from not cleaning the baby bottles good enouph.. i dont think it is .. what do you think please respond..thank you|||Why don't you just start boiling the bottles after washing them then watch to see if the rash goes away. It couldn't hurt anything.|||dont' worry those are just birth marks...they go away with age...TOTALLY normal...