picking at the fingernails
Onychotillomania is a compulsive neurosis in which a person picks constantly at the nails or tries to tear them off. It is not the same as onychophagia, where the nails are bitten or chewed or dermatillomania, where skin is bitten or scratched. It is commonly associated with psychiatric disorders such as depressive neurosis, delusions of infestati...
compulsive picking at the fingernails
<psychiatry> A tendency to pick at the nails. ... Origin: onycho-+ G. Tillo, to pluck, + mania, insanity ... (05 Mar 2000) ... 
(on″ĭ-ko-til″o-ma´ne-ә) compulsive picking or tearing at the nails.
Type: Term Pronunciation: on′i-kot′i-lō-mā′nē-ă Definitions: 1. A tendency to pick at the nails.
onychotillomania An excessuve neurotic tendency to pick at (or to pull out) one's finger, or toe, nails.