Efficacy and safety of a dimethicone lotion in patients with pyrethroid‐resistant head lice in an epidemic area, Okinawa, Japan
| Autor: | Yuka Okamoto, Kenzo Takahashi, Hitoshi Kawada, Ryo Yasumura, Sayaka Yamaguchi, Takuya Miyagi, Yuko Okubo |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Adult
Veterinary medicine Insecticides Pediculosis Dermatology 030207 dermatology & venereal diseases 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Japan dimethicone parasitic diseases Pyrethrins Medicine Animals Humans Dimethylpolysiloxanes head lice Nymph Adverse effect Epidemics Pyrethroid pyrethroid business.industry Incidence (epidemiology) Pediculus Knockdown resistance General Medicine Original Articles Lice Infestations medicine.disease chemistry 030220 oncology & carcinogenesis Lotion Population study Original Article business knockdown resistance mutation pyrethroid resistant |
| Zdroj: | The Journal of Dermatology |
| ISSN: | 1346-8138 0385-2407 |
| Popis: | Pyrethroid insecticides are the only pesticides approved for the treatment of head lice (pediculosis capitis) infestations in Japan. However, in Okinawa Prefecture, 96% of head lice are resistant to pyrethroids. Here, we conducted a clinical trial to assess the safety and efficacy of a dimethicone preparation against head lice infestations in Okinawa Prefecture. Dimethicone‐containing lotion was applied over the entire scalp three times over a 7‐day period. Lice bodies (nymphs/adults) and eggs (nits) were counted before (day 0) and after treatment (day 8); a subset of eggs was collected to estimate viability based on hatch rate. Efficacy was evaluated based on improvement (reduction) in head lice counts post‐treatment with respect to baseline. Safety was evaluated based on subjects’ scalp condition and adverse event incidence. Utility was a composite end‐point combining efficacy and safety. In total, 35 subjects were enrolled. Efficacy and safety were evaluated in 23 and 35 subjects, respectively. No side‐effects of note were reported during the treatment period. The dimethicone lotion resulted in a utility rating of “marginally useful” or higher in over 80% of the study population, signifying the formulation to be both safe and effective. The dimethicone lotion was also a potent ovicide; 99.4% of eggs collected after treatment failed to hatch when incubated. Eradication of head lice remained successful for at least 4 weeks after the final topical dimethicone application in 25 of the 28 subjects reached by telephone survey. Lice bodies and eggs were genotyped to analyze the prevalence of three knockdown resistance (kdr)‐type mutations within the voltage‐sensitive sodium channel known to confer pyrethroid resistance. One or more kdr mutations were confirmed in 30 of the 32 subjects from whom specimens were collected (93.8%). Dimethicone was confirmed to be both safe and effective in treating pyrethroid‐resistant head lice. |
| Databáze: | OpenAIRE |
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