Hi..
Can understand your concern..
As per your complain thick and foamy saliva along with dryness of mouth can be a symptom of
burning mouth syndrome which can occur due to damage to major
salivary gland,side effect of medication,
nerve damage,
autoimmune disease like Sjogren's syndrome etc..
In your case if the doctor has asked you to
consult Rheumatologist and explained that it is due to attack on immune system it seems that he is suspecting Sjogrens syndrome and it can be a more confirmed diagnosis if you have dry eyes along with dry mouth as a symptom as both of these are hallmark of Sjogren's syndrome..
For this referring a Rheumatologist is correct as they deal with auto immune diseases and Sjogrens syndrome is one among those..
In case of Sjogrens syndrome to relive dry mouth saliva substitutes containing Methyl cellulose cam be used..
Saliva stimulants like sour candies and sugar free chewing gums can be helpful to stimulate the salivary glands to produce more saliva..
Pilocarpine drug also helps in stimulating saliva flow..
Hope this information helps..
Thanks and regards..
Dr.Honey Nandwani Arora..