Adrenaline-induced local sweating and vasoconstrictive responses in atopic skin

Sweating and vasoconstrictive responses to intradermal injections of adrenaline were studied in the normal-looking back skin of young adult males with atopic dermatitis (AD) and in non-atopic controls using five concentrations of adrenaline, and further in a subgroup of subjects with dry-looking AD skin using two concentrations of adrenaline. The sweating responses were measured with an evaporimeter and the area of blanching determined with planimetry. The maximal sweating response in the AD group was elicited with the suprathreshold concentration of 5 x 10(-6) mol/l and in the non-atopic group with a 10-fold higher concentration. At the three higher concentrations the sweat rates levelled out in both groups and remained at a lower level in AD subjects. The sweating responses in dry-looking AD skin were lower than in non-atopics (P less than 0.001) and were also lower than in those with AD normal-looking skin (P less than 0.05) with both concentrations. In contrast to sweating, the vasoconstrictive reactions showed similar dose-dependent increases with all tested concentrations in AD patients with normal-looking skin and in the non-atopic controls. In patients with dry AD skin the vasoconstrictive responses were also similar to those in non-atopic controls.