Bright red recurring rash on face - allergy?

[Liveinthepresent]

Hi i am a bit clueless about allergies so need some advice.
My DS (almost one) has had a bright red rash on his chin and cheek that comes and goes on a day by day basis but never really clears up.
Initially we thought it might be a teething rash but it has gone on for 8 weeks and he is no longer actually teething right now.
We saw our GP who said it was a slightly infected dribble rash being made to flare up when he eats. We were prescribed Fucidin and told to use diprobase to moisturise.
It is no better after two weeks - and again today is has gone bright red and it feels hot to touch and gets itchy.
What do you think - could this be an allergic reaction?
I am getting a bit stressed as he isn't eating at all well and seems to have stomach pain at night too - I just don't know where to start. I had been avoiding dairy too after some post tummy bug intolerance but now feel like I might be feeding him all sorts of things that are causing discomfort.
By way of background DH side of family are very atopic - and DD gets mild eczema too - and seems allergic to tomatoes though this hasn't been tested for. (GP said even if it was proven with eczema there would be other triggers so it wasn't really worth it)
Any thoughts would be much appreciated.

I'm interested in responses. I have a DC with a permanent rash around the mouth, sometimes flares up more than other times. It's been suggested it is impetigo, infected eczema, topical dermatitis & probably some other stuff. We've used Fucidin, diprobase, aveeno… Had good results with aveeno but it hans't kept it away...

Sounds like eczema.

My daughter got this before her allergies were diagnosed.

I would push for a referral re his allergy and allergy tests.

aprovinciallady am glad it's not just me. I think I need to pursue my allergy instinct. Might try aveeno too.

fanjo ( great name) yes I will go back to GP - I hope they will take it seriously. It looks nothing like DH or DD eczema but I know that doesn't rule it out.

Obviously pursue the allergy route but my DD has a similar rash on cheek and chin and it's just from dribble, even when she's not teething (she gets it on the cheek from drooling in the night and then lying in it!). Putting sudocrem on it before bed and in the morning has really helped so you could try that too.

thanks noble that gives me hope it might be nothing.
It is so hard when they are little and you can see they aren't quite right but can't be sure whether you are over reacting or not.
He is really not himself but that may have nothing to do with the rash!

My DD gets a rash on her face (flaky type) if she has any dairy at all, even in baked goods.

She gets hives if she has eggs.

OP, How old is your LO? Since when has he or she had a rash?