Use italics for the first case of a new or technical term, a key term, or a label. Don't italicize the subsequent appearances of new or technical terms or key terms.

Do you italicize terms in MLA?

The MLA Style Center

The MLA style discourages the use of italics in academic prose to emphasize or point, because they are unnecessary—most often, the unadorned words do the job without typographic assistance.

Do you italicize keywords in APA?

Keywords: should be italicized, followed by a space. The words themselves should not be italicized. You can see an example under the abstract in this APA Style sample paper.