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)