Skin conductance responses in paediatric Harlequin syndrome

We report a novel and simple application of skin conductance response (SCR) testing for diagnosis of a new-onset iatrogenic Harlequin syndrome in an i nfant. Isolated ipsilateral facial pallor, complicated by thermally induced systemic sympathetic vasodilatation, and preferential lateral decubitus po sitioning, mimics harlequin colour change. Correct diagnosis as Harlequin s yndrome with facial sympathetic interruption was demonstrated by diminution of SCR.