Head Lice Are Frequently Misdiagnosed Resulting in Missed School Days and Inappropriate Medication

For immediate release: August 09, 2000

Boston, MA--With a new school year beginning in a few weeks, researchers at the Laboratory of Public Health Entomology at the Harvard School of Public Health (HSPH) have found that health care workers, parents and school officials often misdiagnose and inappropriately medicate head lice infestations. Their study is published in the August issue of The Pediatric Infectious Diseases Journal.

Via their informational website, the researchers asked readers to submit samples of what they thought were head lice or louse eggs. The readers completed questionnaires that asked them their relationship to the infested person and the measures taken to treat the perceived infestation.

"An uncomfortably large proportion of the submissions had nothing to do with head lice, yet in every case someone suspected they were head lice or louse eggs," said Richard Pollack, instructor in immunology and infectious diseases in the Department of Immunology and Infectious Diseases and lead author of the study.

Of the 614 submissions, 41 percent had nothing to do with head lice, but instead were objects such as other types of bugs, dandruff, scabs, knotted hair, and clothing fibers. Of the submissions that were associated with lice, about half seemed to be signs of infestations that were now extinct. Only active infestations (consisting of lice and/or live eggs) should be treated, write the researchers.

The researchers also asked who had made the initial diagnoses. Relatives, mostly parents, were the most likely to correctly identify lice or their eggs, but only about half of those identifications involved active infestations. School nurses also were likely to spot such evidence, but physicians were less accurate.

Pollack said proper instruction and evaluation of lice and their eggs with suitable magnification would help parents and health workers better identify active infestations and curb unnecessary treatment. Although head lice may occasionally be annoying, they should not cause infested children to be sent home from school, said Pollack.

"Schools frequently quarantine children because of the mistaken beliefs that head lice are a health problem or are associated with parental neglect," said Pollack. Lice generally are transmitted by direct contact between affected people.