Acne on back and neck ??

[Scoiland]

I have been on proscar and minoxidil for 8 months and nizoral for about 2

Now recently i have been noticing like underground zits ( the ones that really hurt )

I have found about 3 on my back, 3 on my neck, and 1 on my forhead in the last week

I have never had acne before in my life. What is going on, is the treatment starting to really kick in now or what??

I have had very good results from this regime in regrowing my hair