PHENOTHRIN LOTION, THE LATEST RECRUIT IN THE BATTLE AGAINST HEADLICE - THE RESULTS OF 2 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<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 inci dence 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. Two subjects treated with carbaryl lotion, one of whom also had evidence of live lice, had viable eggs at four weeks, again probably due to re-infestation. A significantly greater incidence of side-effects (p<0.05) was found in the carbaryl lotion treatment group, which were again of a mild cutaneous nature. These studies demonstrate the safety and efficacy of this phenothrin lotion and suggest that it would be a useful and acceptable addition to the currently avail able range of insecticidal preparations. © 1991, Sage Publications. All rights reserved.