Citronella is obtained from the leaves and stem of the Cymbopogon
winteratus or Cymbopogon nardus plant. It is a popular ingredient in
wax candles as an insect repellent; it is also widely used in
perfumes, soaps, skin lotions and deodorants. According to the
researchers, it also has therapeutic potential with antiseptic and
stimulant properties.

The team gave parents a special slow-release, microencapsulated
citronella formulation (oil droplets coated by a positively charged
biopolymer called chitosan, not yet available) for use on half of the
children. The same formulation without the active ingredient was given
to parents for use on the control group.

None of the team members knew who received the active ingredient
(until code numbers were opened after the results were obtained). The
parents were contacted by phone several times to make sure they knew
how to use it on their children's heads.

The children were examined by team members two months later. Only 12
percent of the children treated with the test repellent were
reinfested, compared to 51% of the children who had the placebo
solution. A third examination two months afterwards showed 12.4%
reinfestation in the test group and 33.7% reinfestation in the placebo
group.

The microencapsulation significantly reduced the odor of the
citronella, which was used in a 3.7% concentration. Mumcuoglu said
that the citronella solution should be used especially in those
children susceptible to repeated lice infestation.

Although they have not yet proved this scientifically, the team
believe