Head lice infestation: single drug versus combination therapy with one percent permethrin and trimethoprim/sulfamethoxazole.
BACKGROUND
Head lice infestation (HLI) is a vexing problem for pediatricians and families because lice are becoming resistant to approved antipediculosis agents.


OBJECTIVE
This study compared the efficacy of 3 different treatments for HLI and determined whether combination therapy reduced treatment failures.


METHODS
A randomized, clinical trial performed in 3 private practices.


METHODS
The population was children ranging in age from 2 to 13 years.


METHODS
HLI was diagnosed by direct inspection of the hair and scalp. Children were assigned to 1 of 3 groups: 1) 1% permethrin creme rinse (1% PER; n = 39); 2) oral administration of trimethoprim/sulfamethoxazole (TMP/SMX; n = 36); and 3) a combination of 1% PER and TMP/SMX (n = 40). Follow-up visits were done 2 and 4 weeks later, and parents or caregivers of those who did not return were interviewed by telephone. If HLI was present at the 2-week follow-up, the child was retreated per their protocol. We defined successful treatment as the absence of adult lice and nymphal stage or eggs (nits). The presence of nits alone was not considered a treatment failure.


RESULTS
At the 2-week follow-up visit, successful treatment for groups 1, 2, and 3 was 79.5%, 83%, and 95%, respectively. At the 4-week follow-up, successful treatment was 72%, 78%, and 92.5% for groups 1, 2, and 3, respectively. The absolute risk reduction for recurrence comparing group 1 versus group 2 was 6%, group 2 versus group 3 was 14%, and group 1 versus group 3 was 20%. No major adverse complications were seen in any treatment group.


CONCLUSIONS
Our findings indicate that a combination of 1% PER and TMP/SMX is an effective alternative therapy for HLI. We recommend that the dual therapy with 1% PER and oral TMP/SMX be used and reserved in cases of multiple treatment failures or suspected cases of lice-related resistance to therapy.
Department of Pediatrics, University of California, Davis, California 95616, USA. rbhipo@aol.com.
R B
RB
Hipolito
F G
FG
Mallorca
Z O
ZO
Zuniga-Macaraig
P C
PC
Apolinario
J
J
Wheeler-Sherman
D000284:Administration, Oral; D000287:Administration, Topical; D000818:Animals; D000890:Anti-Infective Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D002648:Child; D002675:Child, Preschool; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D007306:Insecticides / Q000008:administration & dosage / Q000627:therapeutic use*; D010373:Lice Infestations / Q000188:drug therapy*; D008297:Male; D010374:Pediculus; D026023:Permethrin; D011722:Pyrethrins / Q000008:administration & dosage / Q000627:therapeutic use*; D012536:Scalp Dermatoses / Q000188:drug therapy*; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000008:administration & dosage / Q000627:therapeutic use*
D000890:Anti-Infective Agents; D007306:Insecticides; D011722:Pyrethrins; D026023:Permethrin; D015662:Trimethoprim, Sulfamethoxazole Drug Combination