Multiple realities(covers information from several alternate timelines)
A piercing was a deliberate hole made in a part of one's body for the purpose of accommodating jewelry, such as earrings or nose rings.
In 1986, a punk encountered by James T. Kirk and Spock on a bus in San Francisco had multiple piercings, including those in his nose. (Star Trek IV: The Voyage Home)
In 2259 of the alternate reality, a Klingon that Nyota Uhura spoke with had multiple piercings in his face. (Star Trek Into Darkness)
In 2368, Clara Sutter described her imaginary friend Isabella as having pierced ears. (TNG: "Imaginary Friend")
By 2375, Dukat had pierced his ear as "a symbol of the covenant I've made with my new family." Upon breaking it later, he pulled out the earring, (DS9: "Covenant")