Is this normal?

My 4months+ son’s left side area nappy area has peeled off skin. I thought it was diaper rash at first but it got bigger it almost look like shedding new layer of skin. He doesn’t seem like in pain because he didn’t cry when i touched the area. I changed to desitin diaper cream (previously been using Pureen) and applied Mustela cicastela cream on the areas that are peeling off & ensured the area is completely dry before application . My mum said it was because i put too much diaper cream that caused the dryness. Shouldn’t it be applied generously? Or was it because of his diaper size? He’s currently using size S, weighing 6.9kg and I thought I shouldn’t size up yet because the tapes are always touching each other when put on. Please advise! #pleasehelp #firstmom #sos #diaperrash #plsadvise #helpandrespect