recurrent itchy rash on elbows, knees, back, thighs and butt

I have been treated for hypothyroidism for 30 years. In the past two years I have developed itchy bumps on my scalp. that I thought was folliculitis. Then the bumps started appearing on my elbows and knees. I saw a dermatologist a year ago and she thought it may be autoimmune. Well now I have these same itchy bumps on the back of my thighs, my back and my butt. The itching keeps me from falling asleep. And now with the COVID-19, I can't get in to see the dermatologist. What am I dealing with?? Has anyone ever had this problem? Taking antihistamines help very little for the itch. I use hydrocortisone sometimes, but I know that I cannot use that for long periods of time. Anyone have any ideas?