Lewis & Short

părōnychĭa, ae, f., and părōny-chĭum, i, n., = παρωνυχία, a whitlow (pure Lat. reduvia), Plin. 21, 20, 83, § 142; 23, 9, 81, § 163.
In neutr., Petr. 31: ad pa ronychia et pterygia unguium, Plin. 24, 19, 119, § 182; 28, 8, 24, § 88.