Hello Risa, I read your message and understood your medical problem. Infection and rash may cause an elevation in the perception of pain. This can be one cause why the pain has increased and became more resistant. After some time the oral cortisone is not any more effective in relieving and preventing the sciatic pain. Other alternatives of treatment must be considered starting with local injections of cortisones or painkillers like anesthetics. You spine doctor must see you and do a full check of your lumbar spine. If the situation indicates surgery you can do it and normalize within two weeks. It is important to avoid pressure on the spine. Do not raise heavy stuff and do not go through any excessive exercise. hope this is helpful