At a healthy level, skin picking is just self grooming and doesn't cause much, if any, damage.
In fact, 99.9% of the population does it in some way, and if you hadn't noticed, all animals groom themselves too! That's why, with my clients, we focus on reducing this behaviour back down to a healthy level.
It's why my clients get results: our goal is realistic, tangible, and doesn't expect perfection from you.