Basically, I have been itching mostly at night, (for about 6 months now non-stop) but sometimes in the daytime, and have been taking a Benadryl for it which 1) puts me to sleep 2) stops the itching. I have eliminated food allergies, mites, and dry skin. Now, I am wondering about autoimmune disorders. Are there any of those disorders or diseases that have itching as a symptom?
Hello. Thank you for asking at Chat Doctor. One most important thing I would like to know is whether you itch without hives/skin lesions/urticaria or with them. If you have hives/urticaria, I would say you are having chronic urticaria. I would suggest you to consult an Allergist who will perform some tests for physical urticaria and suggest some blood tests like total blood count, ESR, serum anti-thyroglobulin antibodies, anti-nuclear antibodies, anti-thyroperoxidase antibodies and urine & stool examination. Some of these tests are for autoimmune disorders. Then he can treat accordingly. But if you are not having skin lesions at all and only itching, I would not think of allergy at first. The causes are many like Chat Doctor.  So I would suggest you to consult a physician who may suggest you tests like CBC, ESR, blood sugar, SEPT, total proteins including albumin & globulin, urea, creatinine and urine & stool routine and microscopic examination. Then he can treat you accordingly. Hope this will be helpful to you. Wish you the best of the health. Regards.