1808 (pernicktie, in Jamieson), of persons, "precise; fastidious; fussily particular, especially about trifles," an extended form of Scottish pernicky, which is of uncertain origin, perhaps somehow from particular. "Association with the knick group of words … may have been vaguely present" [OED].

Source : Online Etymology Dictionary

Note: The Online Etymology Dictionary maintains a free-access list of the origins of thousands of English words, a significant proportion of which are unknown