Background Hyperhidrosis is the secretion of inappropriately large amounts of sweat by eccrine glands; it can be very debilitating. Little is known of the causes of primary hyperhidrosis.
Objectives To determine whether the glands exhibit any structural abnormality in primary hyperhidrosis.
Methods Skin biopsies were obtained from the axilla (n = 6) or neck (n = 2) of individuals aged 26–62 years with primary hyperhidrosis and from five age- and sex-matched normal individuals, with informed consent and ethical committee approval. Samples were prepared by standard methods for light and electron microscopic examination.
Results All characteristics observed in the hyperhidrotic specimens were consistent with the changes seen in normal glands following strong activation: degranulation of the granular (dark) cells, dilatation of the basolateral infoldings and the canaliculi of the non-granular (clear) cells, contraction of the myoepithelial cells and thickening of the basal lamina, and presence of cellular debris including lipid droplets in the gland lumen. Pathological changes were not observed.
Conclusions The present finding of the absence of structural defects in the glands indicates that future studies should concentrate on the investigation of neurohumoral or secretory cell metabolic abnormalities.