Nose picking has a name called "rhinotillexomania "!

When nose picking becomes a body-focused repetitive behavior or obsessive–compulsive disorder it is known as rhinotillexomania.
The environment of the nose, and the dried secretions removed, contain many microorganisms. When a person is contagious with a cold, flu or other virus, it is important that hands or other objects used to remove mucus are washed promptly because there is risk of introducing microorganisms to other parts of the body or other people. When a person is not contagious, the act of picking and eating one's own nasal mucus can be therapeutic in that it may provide immuno-health benefits. Picking one's nose with dirty fingers or fingernails may increase risks of infection that may include an increase in the diversity of nose flora (and thus infection or illness), or occasional nosebleeds. One case of rhinotillexomania resulted in perforation of the nasal septum and self-induced ethmoidectomy. Nose picking, however, should not affect the sense of smell, as the nasal cavity where the olfactory nerves are located is too high up to reach.

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