stiffness due to plantar fasciitis, an inflammatory
condition involving the sole of the foot, is relieved by "iontophoresis"
treatment with acetic acid, Australian investigators
report. Iontophoresis refers to the use of a small
electric current to move ionized substances through the
skin into tissues. There have been reports that
iontophoresis with the steroid dexamethasone or acetic
acid benefits patients with plantar fasciitis, Drs. H. R.
Osborne and G. T. Allison explain in their study,
published in the British Journal of Sports Medicine.
However, there have been no comparisons of the two agents.
The investigators based at the University of Western
Australian in Perth therefore conducted a randomized trial
among 31 patients with symptomatic plantar fasciitis for
at least 1 month.
The treatments consisted of iontophoresis with
0.4% dexamethasone, 5% acetic acid,
or saline "placebo." The patients got six treatments with
an iontophoresis drug delivery system, applied to the site
of maximum tenderness, over a 2-week period.
Treatment was delivered while the patients also had taping
to support the arch of the foot, intended to relieve
pressure on the midfoot area of the sole. Patients
reported measures of pain and stiffness at the start of
the study, after 2 weeks and after 4 weeks, using a 0-10
At the end of 2 weeks, all three groups reported
significant improvement in morning pain and average pain
in the preceding week, but acetic acid was the most
effective. By the 4-week follow-up visit, the effects of
the treatment on pain were diminished, but there was still
an overall improvement with acetic acid treatment and to
some extent with dexamethasone. In terms of morning
stiffness, all three treatments reduced this symptom, but
the difference was statistically significant only in the
acetic acid and placebo groups. The reduction in stiffness
was maintained only among patients treated with acetic
Osborne and Allison conclude, "For
the best clinical results at four weeks, taping combined
with acetic acid is the preferred treatment option
compared with taping combined with dexamethasone or saline