I'm not sure if you found what other here have posted on oral thrush, but this might be helpful: https://www.celiac.com/search/?q="Oral thrush"&quick=1&updated_after=any&sortby=relevancy

If you have DH you will likely also want to avoid iodine, which is common in seafoods and dairy products, as it can exacerbate symptoms in some people. This article may also be helpful as it offers various ways to relieve the itch:  

Welcome to the forum, @JulieRe! You would do well to get checked for a candida infection of the gut. Yeast thrives on carbs so you might also look into a low carb diet. These kinds of things seem to be more common in the celiac community than in the general population. There is a growing body of evidence that the development of celiac disease is rooted in unhealthy gut biome conditions. It's good that you are getting that red spot on your tongue checked out soon. It's likely related to the thrush but I would also not rule out a neoplasm which you would certainly want to catch early.

Hi there! I have very similar dermatitis herpetiformis responses. The only thing that helps is dissolving a Benadryl pill and rubbing that on the painful itchy spots that arise on my knees, scalp, elbows. I have been working with a nutritionist who also has celiac we narrowed down to me only getting we certified gluten-free products - which I try the best I can. But then I have found products that use guar gum and other additive gums I have reactions as well. It was my plant based milk. I had to switch to Elmhurst it’s just nuts and milk- most of the time.   I hope that’s helpful! I’ll keep following:) we seem to have very similar reactions! 

Hi,  My name is Julie and I am new to the forum.  I have been diagnosed with Celiac disease since 2006.  I follow a strict gluten free diet. In July I was diagnosed with oral thrush.  I had swollen lips, and my tongue was very red towards the front.  I also had a weird taste in my mouth and very dry mouth despite drinking lots of fluids.  I went to Urgent care and was prescribed fluconazole oral tablets for 5 days and it essentially cleared up.  Has anyone else had this happen?  It was so strange.  The doctor thought the thrush was from my mouth guard I wear at night.  Although my cleaning process had not changed. Also today I noticed an abnormal red spot on my tongue.  No other symptoms.  I will be calling my dentist.  But am curious if anyone has had trouble with yeast in their gut. Thanks Julie