Cut off the affected leaves. Spray - that means hitting under leaves, over leaves, stems, every part of the plant - a mix of milk diluted 5:1 with water. You'll need to keep doing this every three days until harvest. The milk will keep the PM under control and you won't have ruined your buds.
Greencure is also effective, however, you can burn your buds if used at too high a mix. Serenade is great during veg but I won't use it during flower.