Phenothrin lotions in the treatment of head louse infestation

WITHDRAWN: Interventions for treating headlice

BACKGROUND

Infection with head lice is a widespread condition in developed and developing countries. Infection occurs most commonly in children, but also affects adults. If left untreated the condition can become intensely irritating and skin infections may occur if the bites are scratched.

OBJECTIVES

The aim of this review was to assess the effects of interventions for head lice.

SEARCH STRATEGY

Cochrane Infectious Diseases Group specialized trials register (July 2002); The Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 2, 2002); MEDLINE and TOXLINE (1966 to July 2002); EMBASE (1980 to May 2002); LILACS (July 2002); Science Citation Index (1981 to July 2002); BIOSIS (1985 to July 2002); reference lists of relevant articles; pharmaceutical companies producing pediculicides (published and unpublished trials); UK and US Regulatory Authorities.

SELECTION CRITERIA

Randomised trials (published and unpublished) or trials using alternate allocation were sought which compared pediculicides with the same and different formulations of other pediculicides, and pediculicides with physical methods.

DATA COLLECTION AND ANALYSIS

Of the 71 identified studies, only four met the inclusion criteria. Two reviewers independently assessed trial quality. One reviewer extracted the data.

MAIN RESULTS

We found no evidence that any one pediculicide has greater effect than another. The two studies comparing malathion and permethrin with their respective vehicles showed a higher cure rate for the active ingredient than the vehicle. Another study comparing synergised pyrethrins with permethrin showed their effects to be equivalent. A comparative trial of malathion lotion vs combing, showed combing to be ineffective for the cureative treatment of head lice infection. Adverse effects were reported in a number of trials and were all minor, although reporting quality varied between trials.

AUTHORS' CONCLUSIONS

Permethrin, synergised pyrethrin and malathion were effective in the treatment of head lice. However, the emergence of drug resistance since these trials were conducted means there is no direct contemporary evidence of the comparative effectiveness of these products. The 'best' choice will now depend on local resistance patterns. Physical treatment methods(BugBusting) were shown ot be ineffective to treat head lice. No evidence exists regarding other chemical control methods such as the use of herbal treatments, when used in the curative treatment of head lice. Future trials should take into account the methodological recommendations that arise from this review.

Interventions for treating headlice

BACKGROUND

Infection with head lice is a widespread condition in developed and developing countries. Infection occurs most commonly in children, but also affects adults. If left untreated the condition can become intensely irritating and skin infections may occur if the bites are scratched.

OBJECTIVES

The aim of this review was to assess the effects of interventions for head lice.

SEARCH STRATEGY

Trials register of The Cochrane Infectious Diseases Group; Medline; Embase; Science Citation Index; Biosis and Toxline; reference lists of relevant articles; pharmaceutical companies producing pediculicides (published and unpublished trials); UK and US Regulatory Authorities.

SELECTION CRITERIA

Randomised trials (published and unpublished) or trials using alternate allocation were sought which compared pediculicides with the same and different formulations of other pediculicides, and pediculicides with physical methods.

DATA COLLECTION AND ANALYSIS

Of the 70 identified studies, only three met the inclusion criteria and one is awaiting assessment. Two reviewers independently assessed trial quality. One reviewer extracted the data.

MAIN RESULTS

We found no evidence that any one pediculicide has greater effect than another. The two studies comparing malathion and permethrin with their respective vehicles showed a higher cure rate for the active ingredient than the vehicle. The third study comparing synergised pyrethrins with permethrin showed their effects to be equivalent. Adverse effects were reported in a number of trials and were all minor, although reporting quality varied between trials.

REVIEWER'S CONCLUSIONS

Permethrin, synergised pyrethrin and malathion were effective in the treatment of head lice. However, the emergence of drug resistance since these trials were conducted means there is no direct contemporary evidence of the comparative effectiveness of these products. The 'best' choice will now depend on local resistance patterns. There is currently no evidence from trials to indicate the effectiveness of physical methods, such as combing/'BugBusting' or other chemical control methods such as the use of herbal treatments, when used in the curative treatment of head lice. Future trials should take into account the methodological recommendations that arise from this review.

Systematic review of clinical efficacy of topical treatments for head lice

OBJECTIVES

To collect and evaluate all trials on clinical efficacy of topical treatments for head lice.

DESIGN

Systematic review of randomised trials identified from following data sources: Medline, International Pharmaceutical Abstracts, Science Citation Index, letters to key authors and companies, and hand search of journals.

SETTING

Trials in schools or communities.

SUBJECTS

Patients infested with lice.

MAIN OUTCOME MEASURE

Cure rate (absence of live lice and viable nits) on day 14 after treatment.

RESULTS

Total of 28 trials were identified and evaluated according to eight general and 18 lice specific criteria. Of the 14 trials rated as having low to moderate risk of bias, seven were selected as they used the main outcome measure. These seven trials described 21 evaluations of eight different compounds and placebo (all but two evaluations were of single applications). Only permethrin 1% creme rinse showed efficacy in more than two studies with the lower 95% confidence limit of cure rate above 90%.

CONCLUSIONS

Only for permethrin has sufficient evidence been published to show efficacy. Less expensive treatments such as malathion and carbaryl need more evidence of efficacy. Lindane and the natural pyrethrines are not sufficiently effective to justify their use.

Phenothrin lotion, the latest recruit in the battle against headlice: the results of two controlled comparative studies

One hundred and one subjects with head louse infestation were entered into two separate studies, in which a phenothrin aqueous/alcoholic lotion was compared to a carbaryl lotion and a malathion lotion. Fifty subjects were treated with a single application of the phenothrin lotion, 28 with the carbaryl lotion and 23 with the malathion lotion. In the comparative study of the phenothrin and malathion lotions an inspection on the day following treatment showed no live lice remained, but that six of the subjects treated with malathion lotion still had evidence of viable eggs (p less than 0.05). In one subject viable eggs were still evident at two weeks post-treatment. There were no cases, however, of live lice or viable eggs at four weeks post-treatment. Mild cutaneous side-effects were reported in five subjects, the incidence of which was not significantly different by treatment group. One subject in the phenothrin and carbaryl lotion comparative study had evidence of live lice at one week post-treatment with phenothrin lotion. This subject received no further treatment and was clear of both live lice and viable eggs at subsequent visits. A separate case of live lice infestation was found at two weeks post-treatment in a subject treated with phenothrin lotion and at four weeks post-treatment in two subjects treated with carbaryl lotion. As these subjects were free of live lice infestation at previous follow-up visits it was highly probable that these were cases of re-infestation from another source.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of phenothrin shampoo and malathion lotion in the treatment of head louse infection

Eighty patients (age range 4-10 years) with head lice infection were recruited to the study. Forty patients were treated with a single application of 0.2% w/v phenothrin liquid shampoo and 40 with 0.2% w/v malathion lotion. Inspection of the patients one week later revealed that no live lice remained in either group, but that two patients had viable eggs in the malathion lotion group. Re-inspection four weeks after application revealed that five patients of the phenothrin shampoo group and seven of the malathion lotion group had viable eggs. Live lice were not seen to be present in either treatment group. The results indicate that both products are effective in the treatment of head lice infection and that the phenothrin shampoo would be a useful addition to the insecticides currently employed.