@Louise Broughton, Some types of interferon drugs can precipitate a Thiamine deficiency, by destroying thiamine and blocking its absorption.  Thiamine deficiency symptoms encompass all the symptoms you listed.  Gastrointestinal Beriberi caused by Thiamine deficiency has symptoms of vomiting, bloating, abdominal pain and diarrhea.  I've experienced this.  I took high dose Thiamine in the form Benfotiamine, and a B Complex. Thiamine can also be low on the Gluten free diet.  Talk to your doctor about supplementing with Benfotiamine and the B vitamins.   Interesting Reading: Gluten-free diet intervention reduces thiamine intake in two weeks, increases glycaemic response and decreases body weight in four weeks, with no long term nutritional deficiencies https://pubmed.ncbi.nlm.nih.gov/34583628/ Thiamine and benfotiamine: Focus on their therapeutic potential https://pmc.ncbi.nlm.nih.gov/articles/PMC10682628/

Hi, @Blue Roan, I have Sjogren's Syndrome that made my salivary glands under my jaw swell.  I also have dry eyes from Sjogren's.  Yes, Sjogren's is yet another fun autoimmune disease that can occur in Celiac Disease.  It starts in the salivary glands. Vitamin D deficiency can also make salivary glands swell.  I was very deficient in Vitamin D also.  Vitamin D is instrumental in regulating the immune system and lowering inflammation. My dentist checked for stones blocking ducts in the salivary glands, too, but I didn't have any of those.  Yeah!  Try cutting out the antihistamines, because they make everything dry up.   Correcting my Vitamin D level to 80-100 nmol/ml has helped immensely.  I also supplement with Omega Threes (flax seed oil, oil of evening primrose) which has also helped my dry eyes and reduced my enlarged salivary glands.   Hope this gives you some direction to go next on your journey.  Wish it was better news.  Keep us posted on your progress!   P.S. Interesting Reading: Association Between Vitamin D and Minor Salivary Gland Inflammation https://pmc.ncbi.nlm.nih.gov/articles/PMC9807185/ Outline of Salivary Gland Pathogenesis of Sjögren’s Syndrome and Current Therapeutic Approaches https://pmc.ncbi.nlm.nih.gov/articles/PMC10342367/

In my case I the rash and marks that present tend to be AFTER I have been scratching the skin, not before.  There are several varieties of eczema.  .   https://www.aad.org/public/diseases/eczema/types A few years ago, I was convinced my son had ringworm.  He had marks all over his torso, and given we live near livestock, I assumed he'd picked something up at the nearby farm.  Took him to the doctor who had seen a lot of different types of rash fully expecting him to agree, and he told me, "No, he's got discoid eczema".  He gave me a cream to put on my son, and it was gone within a few days and has never come back.  I think then it was to do with bubble bath we were using. Do you use that sort of thing? If so, do use hypoallergenic products, and make sure you rinse properly.  I remember one dermatitis saying only reserve 'heavy soaping' for under the arms.  Any large areas of skin which don't look dirty just need water.  This has been helpful.  A good emollient cream would be good too, for eczema sufferers, to be put on straight after your shower or bath.    Another tip that I have found helpful is 'treat any new outbreak'.   If I do that, I find it really stops it spreading.  I hope you get to see a dermatologist soon, but for the meantime do keep a food diary.  Try to identify all the foods that are causing your eczema and mouth symptoms.  I am sorry your doctors are being so dismissive of your symptoms as those sound very real to me.  I have a friend who has experienced the same and she couldn't get any doctors to believe her either.  In the end she paid for a private allergens test and it turned out yeast was a huge trigger for her.

Are you scratching hard enough to leave bruising -- the dark marks?  But no rash?  And worse with exercise?  And no flaking?   I had vitamin deficiencies that caused neuropathy - itching, buzzing, tingling sensations, that I would scratch until I left bruising.   Many of the B vitamins, if deficient, can cause this itchy feeling without a visible rash on top of the skin.  Vitamins B12 Cobalamine, B6 Pyridoxine, Niacin B3, and Thiamine B are important to nerve transmission.  The B vitamins can be low in gluten free diets and deficiencies worsen over time.  I supplemented with a B Complex and extra Thiamine in the form Benfotiamine and relieved the itchy feeling. Are you taking any supplements?  Have you been checked for nutritional deficiencies recently?   The B vitamins are water soluble, so any excess is p'd out if it's not needed.  Try supplementing with B Complex and Benfotiamine to see if it helps.  

It’s interesting you mention eczema I had that as a child. Use to get it on my arms and hands . I wasn’t sure if this was the case again, because my skin isn’t flaky, I don’t have a rash like I did in childhood.  But similarity I notice certain foods really triggers the itch. Rice, is a major tigger when I eat rice I end up itching all night long. I can do oats too but it makes my mouth and tongue go numb after eating them. I try to avoid it.  🤔 on the blood work, I haven’t had any done in a while. It’s difficult speaking to doctors at times as they dismiss it as psychological. But I’ll keep pushing for an answer. Thanks to everyone who replied I really appreciate it.