I picked a spot and now it is an open wound. Should I use an acid?

Skip exfoliating acids on the open area. For a small superficial wound, gentle cleaning, a little plain petroleum jelly, and an appropriate dressing can support healing. Once the surface is closed and calm, you can reassess pigmentation or acne treatment without putting actives directly onto injured skin.

Treat the open skin first

Seek medical care for a deep wound, increasing pain, or signs of infection rather than continuing cosmetic treatment.