Question: What is the cause of Phthiriasis Palpebrarum?

Context:
Phthiriasis palpebrarum is an uncommon cause of blepharoconjunctivitis in which Pthirus pubis infest the eyelashes. We report a case of unilateral phthiriasis palpebrarum with crab louse. 
BACKGROUND: Pediculosis capitis is a common parasitic infestation, whereas phthiriasis palpebrarum is an uncommon infection due to Phthirus pubis (pubic lice) inoculating the eyelashes and surrounding tissues of the eye. 
Head lice typically do not infect the eyes, and given the different morphology of the lice on the patient's head and eyes, a diagnosis of phthiriasis palpebrarum was made. 
P. pubis can cause pruritic eyelid margins or unusual blepharoconjunctivitis. We present a case of phthiriasis palpebrarum in a 4-year-old boy.
INTRODUCTION: Phthiriasis palpebrarum is an ectoparasitosis in which Phthirus pubis infest the eyelashes.
In all cases, the diagnosis of phthiriasis palpebrarum was confirmed by parasitological examination of eyelashes, which revealed the presence of adult and nit forms of Phthirus pubis.
 Based on the observation of numerous nits at the base of the eyelashes and the ectoparasite in the palpebral margin, a diagnosis of phthiriasis palpebrarum was made.
Phthiriasis palpebrarum (lice infestation of palpabrae) is a rarely reported disorder and may present as blepharoconjuctivitis. 
Phthiriasis palpebrarum (PP) is a rare eyelid infestation caused by phthirus pubis.
Phthiriasis palpebrarum, caused by Phthirus pubis, is an uncommon cause of blepharoconjunctivitis; therefore, this condition is easily misdiagnosed
Phthiriasis palpebrarum, caused by the phthirus pubis, is a rare cause of blepharoconjunctivitis, and is therefore often neglected
Phthiriasis palpebrarum is an uncommon cause of blepharoconjunctivitis in which Pthirus pubis infest the eyelashes
Phthiriasis palpebrarum is an unusual cause of blepharoconjunctivitis and may easily be overlooked because of the failure of physicians to recognize Phthirus pubis
Phthiriasis palpebrarum (PP) is a rare eyelid infestation caused by phthirus pubis
Phthiriasis palpebrarum, caused by the phthirus pubis, is a rare cause of blepharoconjunctivitis, and is therefore often neglected. 
Phthiriasis palpebrarum is an infestation of the eyelashes caused by the louse Pthirus pubis (Linnaeus, 1758). 
Phthiriasis palpebrarum, caused by Phthirus pubis, is an uncommon cause of blepharoconjunctivitis; therefore, this condition is easily misdiagnosed.
Phthiriasis palpebrarum, caused by the phthirus pubis, is a rare cause of blepharoconjunctivitis, and is therefore often neglected.
Phthiriasis palpebrarum is an uncommon cause of blepharoconjunctivitis in which Pthirus pubis infest the eyelashes. We report a case of unilateral phthiriasis palpebrarum with crab louse.
Phthiriasis palpebrarum is an infestation of the eyelashes caused by the louse Pthirus pubis (Linnaeus, 1758). We report a case of phthiriasis palpebrarum in a 6-year-old girl, which was initially misdiagnosed as allergic blepharoconjunctivitis.
Phthiriasis palpebrarum is an unusual cause of blepharoconjunctivitis and may easily be overlooked because of the failure of physicians to recognize Phthirus pubis.

Answer: Phthiriasis palpebrarum is a rare eyelid infestation caused by phthirus pubis.
Exact answer: Pthirus pubis