Hi, I Had Small Smooth Patch On My Scalp Where

Hi, I had small smooth patch on my scalp where hair was lost and it started gradually increasing. when i consulted doctors they said its scarring alopecia and it does not have any treatment and they can try steroid but even that will not help. I have seen some videos on you tube that onion juice can help in scarring alopecia as well if applied for long time or one can go for Homeopathic treatment for this. Request you to pls advice if this disease is curable by anything....