Severe puss bumps all over head scalp.

I've been suffering this problem for more than 17 years.. Initially it started with one or two pimple like things filled with puss on scalp. Now these puss bumps have grown in size and occur almost every where on my scalp excluding bald area. Consulted multiple doctors. Problem disappears when on medication. When medication is stopped. Tests were also got done and doctors gave medicines again but no relief. One of doctor told that he can give powerful medicine but that may affect kidneys and suggested using current medicine. Continued same but no relief. This was case some 10 yrs back. From then onwards I am using medicines when ever there are bumps and stop once they are gone. Again use medicine when they occur again. Used antibiotics(gudcef cv 200, azithromycin.) dint remember the tabs I used initially and shampoos (candid TV, ketone, Nizoral, ketaconozole). Last year consulted a doctor hoping for permanent recovery but he was money minded and kept me on repeated medic.