@simrin--Have you tried an anti-fungal scalp folliculitis treatment at all?
If the folliculitis is caused by an immune system problem, you might have to take low-dose antibiotics for the long term. That's what my brother is doing. His doctor believes that his folliculitis is a genetic problem and only a low-dose antibiotic or acne medication can keep it under control. So he's on low dose antibiotics and probably will be indefinitely.
You might also want to support your immune system with multi-vitamins and antioxidants. I've heard that vitamin A, vitamin D, omega-3 and zinc is really important for the immune system. So have some blood work done to see if you have a deficiency in any of these. And ask your doctor what he or she would recommend you to take and support your immune system that way.