I Have Been Fighting A Rash Since Last July It

I have been fighting a rash since last July it comes and goes it started out on the under side of my wrist and my elbow then on my stomach and arms then started effecting my legs and my back looks like measles or small pimples i have big spots that look like dry skin and now a lump on both sides of the back of neck left size bigger an scalp is itching and flaking like crazy family doctor said dermatitis and the dermatologist said mites and gave me 7 pills and cream nothing is helping and I'm miserable the dermatologist seen no mites but said it resembles what mites do