Validation of the cantharidin-induced blister method in Complex Regional Pain Syndrome

In research with Complex Regional Pain Syndrome (CRPS) patients, bioactive
substances are being measured in blister fluid from the involved hand or foot
in comparison with the non-involved hand or foot. This reflects disease
activity and displays effectiveness of pharmaceutical intervention during the
course of the disease.
In order to replace the so far standard vacuum blister method by a more
convenient method, the usefulness should be tested simultaneously, both in
healthy controls and CRPS patients in the acute (inflammatory) phase and the
chronic (trophic) phase of the disease. It is not known whether locally formed
mediators are reflected similar by these two methods.

This pilot study will be performed to investigate whether the
cantharidin-induced blister method is a useful alternative for the vacuum
blister method in patients with acute or chronic CRPS.
Replacement of the vacuum blister method by the filter disc method could be
more appropriate for the patient and result in better blisters with higher
quantities.

In a parallel study blister fluid obtained after induction of cantharidin or
vacuum suction, measurements to compare the concentrations of bioactive
substances will be performed.

A disadvantage could be the application of another blister which has been
generated by the cantharidin containing filter disc. The healing of this
blister should be faster as the vacuum suction blister, which in some cases
reveal scars.
The simultaneous induction of these two types of blisters is not time consuming
nor expected to induce risk factors.