Hi..
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain it seems that a
white patch over the tongue that has recurred again and is seen specifically during
cold can be due to oral yeast infection also known as
Oral Thrush..
When during other infection, the body's immunity goes low, the oppurtunistic infections can multiply and cause infection..
I would suggest you that when she has the white coat over the tongue, during that duration consult an Oral physician and get evaluated and he can do a clinical evaluation and can also advise you microscopic examination of the scraping from tongue to confirm the diagnosis..
He can advise you to take anti fungal mouthwash like
Nystatin mouthwash, suck Clotrimzole lozenges and take ample of probiotics like Yoghurt and garlic..
Drink plenty of water and maintain a good
oral hygiene..
Hope this information helps..
Thanks and regards.
Dr.Honey Nandwani Arora.