It happens. A call from the school or daycare sets off a frenzy of shampooing, combing and various delousing efforts that has the whole family feeling creepy.
Female head lice lay eggs directly onto strands of hair, and they cement them in place with a glue-like substance, making them incredibly hard to remove. In fact, the eggs are glued down so strongly that they will stay in place even after hair has been treated with pediculicides — substances used to kill lice, a release from the Entomological Society of America says.
Some shampoos and conditioners that contain chemicals or special oils are marketed as nit removal products. However, new research published in the Journal of Medical Entomology shows that ordinary hair conditioner is just as effective.
Scientists in Belgium gathered 605 hairs from six different children. Each hair had a single nit attached to it. Approximately 14 per cent of the eggshells contained a dead egg, whereas the rest were empty.
They then tested the amount of force needed to remove the eggs. Nits on the hairs that were left completely untreated were the most difficult to remove. Eggs on hairs that had been soaked in deionized water were much easier to remove, as were the eggs on hairs that had been treated with ordinary hair conditioner and with products specifically marketed for the purpose of nit removal.
“There were no significant differences in measured forces between the ordinary conditioner and the commercial nit removal product,” the authors write. “The commercial nit removal products tested in the current study do not seem to have an additional effect.”
The authors hypothesize that the deionized water was effective because it acts as a lubricant, so less friction is needed to remove the nits from the hairs. The same goes for the conditioners.
“Treatment with conditioner reduces the coefficient of friction of undamaged and damaged hair,” they write. “As a consequence, conditioners will facilitate nit removal.”