What to do? Help!

Baby is 3 months he has been in and out of this rash thing but it's never been this bad...whats weird it got better at the in-laws over the weekend and then got home and this started happening...nothing has changed....ive washed his face least 4 times in the last day and half...everytime I notice it's dry...today I used Vaseline I know its been only an hr but only made it feel soft not changed the red or bumpy...the only thing I can think of that happened different is I used different body wash with very little fragrance and his lotion was Johnson and Johnson instead of aveeno...I have no clue what to try. Husband wants to do hydrocortisone but idk...