The Collaborative International Dictionary
Phthiriasis
Phthiriasis \Phthi*ri"a*sis\, n. [L., fr. Gr. ?, fr. ? louse.] (Med.) A disease (morbus pediculous) consisting in the excessive multiplication of lice on the human body.
Wiktionary
phthiriasis
n. 1 (context medicine English) An infestation with crab lice 2 A pediculosis