Repellency of citronella for head lice: double-blind randomized trial of efficacy and safety.
BACKGROUND
Head lice move easily from head to head. The lack of safe, effective repellents leads to reinfestation.


OBJECTIVE
To test the efficacy of a slow-release citronella formulation as a repellent against the head louse.


METHODS
During 4 months in 2003 a randomized, placebo-controlled double-blind clinical study was conducted in four elementary schools; 103 children were treated with the test formulation and 95 with a placebo.


RESULTS
A significant difference was observed during the second examination 2 months later, when 12.0% of the children treated with the test repellent and 50.5% of those treated with placebo were infested with lice. A significant difference was also observed at the third examination 2 months later, when 12.4% of the children treated with the test repellent and 33.7% treated with placebo were infested. Overall, there were significant differences between those treated with the repellent and those treated with the placebo (15.4% and 55.1% respectively, P < 0.0001). Side effects were observed in 4.4% of children who disliked the odor of the formulation, and an additional 1.0% who complained of a slight itching and burning sensation.


CONCLUSIONS
Use of an effective repellent could significantly lower the incidence of reinfestations, which would lower expenditure on lice control, including pediculicides, combs and products for nit removal, and the time spent on treatment and removal of the nits.
Mumcuoglu
Kosta Y
KY
Department of Parasitology, Hebrew University Medical School, Jerusalem, Israel. kostam@cc.huji.ac.il
Magdassi
Shlomo
S
Miller
Jacqueline
J
Ben-Ishai
Fiameta
F
Zentner
Gary
G
Helbin
Valery
V
Friger
Michael
M
Kahana
Frigita
F
Ingber
Arieh
A
D000293:Adolescent; D017677:Age Distribution; D000818:Animals; D002648:Child; D031743:Cymbopogon; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007302:Insect Repellents / Q000627:therapeutic use*; D007557:Israel / Q000453:epidemiology; D010373:Lice Infestations / Q000188:drug therapy* / Q000453:epidemiology / Q000517:prevention & control; D008297:Male; D010374:Pediculus / Q000187:drug effects*; D008517:Phytotherapy / Q000379:methods*; D018515:Plant Leaves; D010938:Plant Oils / Q000627:therapeutic use*; D018547:Plant Stems; D012536:Scalp Dermatoses / Q000188:drug therapy* / Q000453:epidemiology / Q000517:prevention & control; D055502:Secondary Prevention; D017678:Sex Distribution; D016896:Treatment Outcome
D007302:Insect Repellents; D010938:Plant Oils