My skin keeps itching and it isn't getting better even after applying medicine.

Sometime ago, I started feeling a strange itching sensation on my skin, so I scratched it. It bled and scabs formed. I initially thought it would get better, but that area started itching continuously. I scratched it occasionally, so I just left it alone. While leaving it alone might have been the biggest cause, the itching persisted even after time passed. I became very worried, thinking it might be shingles. However, it doesn't seem to be herpes simplex. It continues to itchy, and it just won't heal. These spots keep appearing as well. To try and cure it, I went to a pharmacy to apply medication and tried various other methods. However, it didn't seem to improve, so I sought treatment at a nearby small clinic and consulted a dermatologist regarding this treatment. After receiving the medication, it feels better. But as time passes, the cycle repeats. Then I go to the hospital again. Then it gets better again. Then it continues to happen. Why is this happening?