Phthiriasis palpebrarum

Phthiriasis palpebrarum is an imcommon eyelid infestation by Phthiruspubis (crab louse) and, less commonly, by the Pediculus bumanus species, P. humanus var. capitis (head louse) and P humanus var. corporis (body louse). The term pediculosis refers to infestation by the two P humanus species and should not generally be used when referring to eyelid manifestations. 

Phthiriasis palpebrarum results from lid infestation by P pubis, the pubic louse. In postpubescent individuals infestation typically occurs in the pubic area, and in children the eyelashes and eyebrows are most commonly involved. In adults phthiriasis is usually transmitted by sexual contact, but in children infestation usually occurs from contact with an infested parent, usually the mother. The lice may also be transferred by fomites such as bedding and towels.The parasite is well equipped for the pubic area or eye region because of its wide body and... 

Severe itching and irritation characterize phthiriasis palpebrarum. Blepharoconjunctivitis, blood-stained thickened discharge from fecal matter on the lid margins, nits, and adult parasites on the eyelashes may all be visible. 

Figure 23-21 Phthiriasis palpebrarum attached to lid. Head (large black arrowy, claws grasping eyelashes (small white arrows ). Fecal matter may be viewed as a dark spot located in the lower end of the louse abdomen (large white arrow). (Courtesy Dr. Laura Kenyon, University of Houston, College of Optometry.)...

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