Phthiriasis palpebrarum: diagnosis and treatment

Phthiriasis palpebrarum is an ectoparasitosis in which Phthirus pubis infest the eyelashes. It is rare and it can easily be misdiagnosed as blepharitis. The purpose of this study is to describe seven cases of phthiriasis palpebrarum so as to discuss its mode of infestation, diagnosis and treatment.

This is a study of all cases of phthiriasis palpebrarum reported in our laboratory. For each patient, an ophthalmic examination and parasitological examination of the eyelashes were performed.

There were five men and two women. Their ages ranged from 4 to 50years with an average of 21.57years. There were four children and three adults. The main symptom was itching of the eyelids. Clinical signs included reddish-brown crusts at the base of the eyelashes in all the cases and visible lice and nits in three cases. Biomicroscopic examination showed lice and nits anchored to the eyelashes in three cases. In the other two cases, the initial diagnosis was felt to be blepharitis. 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. The number of adult lice ranged from 1 to 30. In all cases, treatment was based on mechanical removal of both the lice and nits. Outcomes were favorable without recurrence.

In conclusion, phthiriasis palpebrarum can be easily diagnosed by close examination of the eyelashes and eyelid margins at the slit lamp and can be managed mechanically. Parasitological examination of the eyelashes can confirm the diagnosis.