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A double-blind, placebo-controlled study on the diagnostic accuracy of an electrodermal test in allergic subjects


Giovanni Passalacqua, Allergy & Respiratory Diseases, DIMI, Pad. Maragliano, L.go R.Benzi 10, 16132 Genoa, Italy. E-mail:


Background Many unconventional diagnostic procedures based on bioelectrical skin responses are presently widely used for allergic diseases, but rigorous experimental evaluations of their accuracy are still lacking.

Aim We assessed whether an electrodermal device can correctly diagnose respiratory allergy.

Methods The diagnostic accuracy of the electrodermal device was assessed in double-blind fashion in 72 allergic patients and 28 healthy volunteers. A random sequence of substances in sealed vials, including histamine, allergens, immunoglobulins at various dilutions and physiological saline, were tested in duplicate in each subject.

Results A wide variability of the measurements was found in most patients irrespective of their allergy status and of the substance tested. Allergic patients showed more negative skin electrical response at the second trial, compared to normal controls, independent of the tested substance. No significant difference in skin electrical response between allergens and negative controls could be detected.

Conclusion We conclude that the studied bioelectrical method, under blind testing, cannot correctly detect respiratory allergy.