Botulinum toxin A for palmar hyperhidrosis: assessment with sympathetic skin responses evoked by train of stimuli

Summary Objective assessment of the effect of botulinum toxin A (BT) treatment in primary palmar hyperhidrosis (PH) is attempted by different methods. We decided to use for this purpose sympathetic skin responses evoked by train of stimuli (TSSR). Twenty patients with severe PH (five female, median age 24, range 18‐36) were examined regularly over 3 months after receiving 50 UI BT in each palm. TSSR were recorded from the palms after sensory stimulation by a train of three supramaximal electric pulses 3 millisecond apart. Results were compared to longitudinally studied TSSR of 20 healthy sex‐ and age‐matched control subjects. All hyperhidrosis patients reported excellent improvement. TSSR amplitudes decreased at week 1 (mean 54% range 48%‐67%) and over the following months in a clinically significant trend (slope R=−.82, P