geographic tongue , really bad smell

my  girl has geographic tongue and has had it from birth, or there abouts .
she had terrible thrush in her mouth as a new baby and has had the geographic tongue constantly since.
she had a notable bad smell from her mouth even at that age.
recently her breath has got so bad that you can not fail to notice it. her room in the morning is shocking .we have even mistaken it as a poo smell.
she also has urticaria pigmentosa . we have been told the breath is probably a result of the geographic tongue could it be a symtem of somthing else?
the smell does not fade with tooth cleaning, mouthwashing or tongue cleaning.
what else can we try /or sugest could be looked into by the GP?
what else can

we also have a 3 year old girl who has geographic tongue and hers oftain looks worse than her sisters but she does not have the smell. i mention her as she has the same diet.