What is the ruling on intentionally extracting what is in a pimple or small wound on the skin, resulting in a little blood coming out, for a fasting person?

There is no obligation upon someone who intentionally extracts blood from their body while fasting, and their fast remains valid. This is because the emission of blood does not affect the validity of the fast, even according to the Hanbalis who consider cupping to invalidate the fast. Therefore, if a fasting person wounds themselves, or if someone else wounds them with their permission, without anything reaching their interior, or by phlebotomy, scarification, or nosebleed, their fast is not broken.