Phthiriasis palpebrarum misdiagnosed as allergic blepharoconjunctivitis in a 6-year-old girl

Abstract

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. Parasites and their nits were found adhering to the eyelashes and eyelids of her right eye as well as scalp hairs. No abnormality was found in the left eye. The histopathology exam revealed the presence of adults and eggs of Pthirus pubis. We mechanically removed all the eyelashes of the right eye at their base, with lice and nits. The scalp was shaved and washed with phenothrin shampoo. No recurrence was found during 3 months of follow-up. Removal of the eyelashes, cutting of scalp hairs, and phenothrin shampoo may be effective in treating phthiriasis palpebrarum. In cases of blepharoconjunctivitis, eyelids and eyelashes should be carefully examined by slit lamp to avoid misdiagnosis.

Phthiriasis palpebrarum in a Spanish infant

“…The parasite usu-ally reaches the eye through hands after contact with the infested genital area or by sexual contact. The crabs are 1-3 mm long and have three pairs of legs [4] (Fig. 3).…”

“…Hypersensitivity caused by louse can lead to secondary conjunctivitis. Clinical signs similar to allergic blepharoconjunctivitis could be found [4]. Thereby a careful slit-lamp examination is necessary to correctly evaluate cases of eyelid inflammation that do not evolve as expected and are resistant to usual treatment [5].…”

<b><i>Phthirus pubis</i></b> Infestation of the Eyelids Presenting as Chronic Blepharoconjunctivitis in a 6-Year-Old Girl: A Case Report

“…Phthirus pubis infestation of the eyelids is commonly misdiagnosed [ 4 ], as symptoms may be confused with other causes of blepharoconjunctivitis. This is due to its infrequency and the difficulties in recognition without performing high-magnification biomicroscopy, owing to the transparent structure of the lice and its localization in the roots of the eyelashes [ 5 ].…”

“…In children, it is usually isolated as in this case because of the lack of terminal hairs on most of their body regions. Associated scalp hair infestation has been reported in children [ 4 ].…”

“…Associated conjunctivitis may result from hypersensitivity to the parasite. Misdiagnosis as allergic blepharoconjunctivitis is possible [ 4 ], hence the need for careful, high-magnification slit-lamp examination in patients with blepharitis with or without associated conjunctivitis.…”