My son is 19 months old and has had a rash on his face for the past 3 months. i thoight it was a heat rash or a rash from drooling but recently i noticed that it has started getting drier more often. what could it possibly be?

A few things: It could be eczema, or the result of a viral infection. If this is a long-standing problem, it's best to pay a visit to your pediatrician so he/she can examine your son.

Could be excema: Excema is relatively a common condition in a child with stable dry skin that does not improve without focused treatment at moisturizing the skin safely. I would have your pediatrician look at this rash, make a correct diagnosis and prescribe a safe, accurate plan of, treatment.

See dermatologist: Hard to tell from your explanation. Could be something simple like eczema. You should consult your pediatrician and if he recommends see a pediatric dermatologist.