Update of the S1 guidelines on the definition and treatment of primary hyperhidrosis.

Focal hyperhidrosis can have a considerable impact on social and occupational activities and be associated with significant impairment in quality of life. Primary (idiopathic) hyperhidrosis is neither caused by systemic disorders nor by external factors. It usually occurs in areas characterized by a high density of sweat glands such as the axillae and hands. The diagnosis of focal hyperhidrosis is based on history and clinical findings. Supplementary diagnostic tests include gravimetry (measurement of the amount of sweat) and the iodine starch test (which shows the area of sweating). Treatment options consist of topical agents, botulinum toxin A injections, iontophoresis, treatment with radiofrequency, microwaves, or ultrasound as well as surgical procedures (axillary suction curettage, sympathectomy). Systemic agents such as anticholinergics may also be used. Selection of the most appropriate therapeutic approach depends on the site affected, prior treatment as well as the patient's requests.