Hi, I Am 23 Years Old And Had A Clear

Hi,

I am 23 years old and had a clear face all my life. Now suddenly a few months back I got a pigmentation mark on nose and small bumps like thin on my face and forehead. These bumps grow to an pimple after some time leaving marks..
Can you suggest what is the cause of this ? I have consulted a doctor and using deriva cms gel for pimples and pigmocare gel for pimentation mark.