I am 26 years old, male, and have white patches of hair in my beard. These patches went from black to white, seemingly overnight. I do not have any grey/white hair anywhere else on the body. The patches of hair on my chin are completely white. Not grey at all, pure white. It started as one patch, and now there are at least 4. They are all located on my chin. Any thoughts? I was assuming it was from stress . Not genetic. No other symptom. Any thoughts?