One cheek red and blotchy?

Ka

We noticed my 2 month old son's cheek is very red and blotchy the other day and we thought maybe he got a bit of a sunburn. Well its now Wednesday and it hasn't gotten any better. Its only on one cheek. I've tried putting eczema lotion on it. Its not warm to the touch so I don't think hes teething. Anyone else ever had this before?