yes it is wise to visit a dermatologist
but if you are afraid the insurance wont cover you what you can do is visit your endocrinologist
since you have thyroid
problems (which might infact cause skin problems ) then your endocrinologist could prescribe a drug that might help you and if not he could refer you to a dermatologist and in this case i think the insurance would cover you.
i hope this answer was helpful if so please rate it as 5 stars.
Best regards ,