Botulinum Toxin in the Management of Focal Hyperhidrosis

Sweating is an important mechanism in the regulation of body temperature. Hyperhidrosis is defined as the production of excess sweat, beyond the amount required to return elevated body temperature to normal, which is slightly below 37°C1. Hyperhidrosis can be divided into primary and secondary forms. Primary, or essential, hyperhidrosis occurs typically in young individuals experiencing mental stress (nervous sweating), without other pathogenetic factors. The sweating is focal and located chiefly in the axillae, the palms of the hands, the soles of the feet, or the forehead. Secondary hyperhidrosis is caused by an underlying neurologic or endocrinologic disease or malignancy. The sweating is usually diffuse (Table 10.1). Primary or focal hyperhidrosis is caused by the overactivity of normal sweat glands and not by glandular hypertrophy. Focal hyperhidrosis is diagnosed in individuals if the area of excess sweating is visibly focal and excessive for at least 6 months without any apparent cause and is associated with at least two of the following characteristics: