I cannot confirm anything without examination,but it can be folliculitis,seat dermatitis,heat rash,diaper rash,contact dermatitis or psoriasis.Looking at the age of the child,diaper or heat rash is a possibility.
Allow your son to wear cotton undergarments and keep the buttocks clean and hygienic.Also after washing the area with water,pat dry the buttocks.Pls do not apply any cream on the byttocks as it will leda to further clogging of pores.You can however apply a light dusting powder.If the rashes still persist,then pls get then evaluated by a dermatologist as antibiotics(in folliculitis) or steroids may be needed.
Hope it helps.Take care and pls do keep me posted on how your son is doing or if you have any additional queries.
We have pretty much ruled out diaper rash. We have tried almost everything out there! From generic to name brand. We have seen a dermatologist but he really didn't do anything for us. He barely even looked at my son! He told us to go with zinc oxide. That's where we started 2 years ago and it didn't help from the get go. I'm not sure what it is but like I said he is always scratchin to the point where he will make himself bleed. *sigh* Have you heard of Freederm HC?? Or know anything else we could try? Thanks!