I thank Dr. Aronson for her interest in this article and welcome her
concerns about its design. I think her point about the next step being a
well controlled trial is an excellent idea.
I would offer the following responses to concerns:
1) Placebo controlled trial: My local county health department
expressed
quite understandable concerns about such an experimental design. To
first prove that all the kids have head lice, then knowingly give half the
kids a sham therapy knowing that these kids will continue to go to
school and expose other kids to contagious lice, was untenable. Thus I
did an open clinical trial in which all the subjects were treated.
2) Wet combing test: This design did not cure patients by the first
wet
combing test alone. Lice were noted in the subjects' subsequent wet
combing tests. Furthermore Roberts et al showed that when wet
combing is done twice a week for several weeks you only get a 38% cure.
(Roberts RJ, Casey D, Morgan DA, Petrovic M. Comparison of wet
combing with malathion for treatment of head lice in the UK: a
pragmatic randomized controlled trial. Lancet. 2000; 356:540-544.)
3) "...in fact not have been infested at the time of this treatment"
We
know subjects were infested at the time they started treatment because
they first had a positive wet combing test.
4) "...suffocation of insects is hard to achieve since many can use
anaerobic metabolism for extended periods": I am aware nits may have
an anerobic metabolism for perhaps the first 2 days of gestation,
however I have not heard this for nymph and adult phase lice. In in vitro
studies, lice kept in dried on suffocation pediculicide greater than 6
hours never survived.
5) "...the same procedures without the Nuvo lotion to be more certain
that the results are valid": In the absence of Nuvo lotion, the only
procedure in this trial which might kill lice would be the heat from the
hair dryer. However, many of these kids before entering the trial had
routinely used hair dryers but still had head lice. It is known that it
requires a 140 degree dryer temperature in the clothes dryer to kill lice.
This temperature cannot be reached on the child's head because it
would burn them.
Sincerely,
Dale Pearlman, MD