Atopic eczema and histamine-induced sensations

Abstract

Background: In previous studies we observed diminished pruritogenic effects and reduced flare reactions after iontophoretic application of histamine in patients with acute atopic eczema (AE).

Objective: To determine a possible mechanism acting on peripheral and central nervous components of the histamine-mediated itch reaction.

Methods: Forty-eight individuals with different predispositions to AE were included. According to an 'atopic score', 16 individuals had no history of atopic symptoms, another group of 16 individuals showed a disposition to AE and a further group of 16 individuals had a clear history of AE. However, all individuals were devoid of acute atopic symptoms and their IgE levels were below 150 U/ml. Histamine was iontophoretically applied to the skin of the forearm, and stimulus-induced itching and burning sensations were rated on visual analogue scales.

Results: Individuals with previous episodes of AE reported weaker itch sensations after histamine. In addition, the sensations were often described as burning by this group.

Conclusion: The results suggest an altered central nervous responsiveness already in symptom-free individuals, since peripheral vascular reactions to histamine were not significantly reduced.