Calcium homeostasis influences epidermal sweating in patients with vitiligo

Patients with vitiligo have a decreased sweating response in both their lesional and non-lesional skin (n=17) compared with healthy age-and sex-matched controls (n=22) after stimulation with the acetylcholine agonist pilocarpine. The decreased cholinergic response of the dermal sweat glands in this patient group correlates with a significantly lower calcium concentration in sweat compared with controls. In addition, a significantly higher potassium concentration was found in the pigmented skin of these patients. The other fast exchange ions sodium and chloride are unaffected. In vitiligo, there was a marginal sweat induction after adrenergic stimulation in four of 10 patients tested whereas all controls (n=10) did not show any response.