Topical lauromacragols and cutaneous neuronal function

BACKGROUND/AIMS: There is evidence that lauromacragols added to topical moi sturizers and bath oils confer additional antipruritic efficacy, The mechan ism for such an effect is not clearly established but lauromacragols may ac t as local anaesthetics. We conducted two studies to determine whether the clinical usage of a topical lauromacragol-containing product could influenc e cutaneous innervation. METHODS: Study I A randomized, double-blind, parallel group trial was perfo rmed in 16 healthy adult volunteers comparing Balneum-(R) (B) and Balneum p lus(R) (BP) bath oils. Study 2 A randomized, double-blind, crossover study was performed in 19 healthy adult volunteers comparing a topical lauromacra gol-containing cream (Optiderm(R)) with placebo. RESULTS: Study I A comparison of the weal, flare and blood flow (measured b y laser Doppler flowmetry, LDF) before and after treatment demonstrated sig nificantly smaller mean flare in the BP group following challenge with calc itonin gene-related peptide (CGRP), Multivariate analysis also demonstrated a significantly reduced LDF measurement in favour of the BP group. Study 2 The only treatment difference that achieved significance was a reduced fla re size in favour of placebo after injection with 48/80. CONCLUSION: Study 1 implies that although lauromacragols in EP might affect neuronal control of the cutaneous microvasculature, the antipruritic effec t claimed for Optiderm(R) does not appear to be due to cutaneous neuronal o r microvascular influences.