Idiopathic localised unilateral hyperhidrosis in a 7-year-old girl: a case report.

Sweating is a physiological process, which is vital for maintaining a constant body temperature and good grip function. Excessive sweating (hyperhidrosis) can on the contrary lead to severe social problems for the affected individual with a decreased quality of life (1). Primary or essential hyperhidrosis is seen symmetrically located to palms, feet, axillae and groins/anogential or generalised in larger areas such as head and trunk. Emotional as well as heat and effort trigger hyperhidrosis in genetic predisposed individuals (2). Essential hyperhidrosis must be differentiated from secondary hyperhidrosis, which is caused by disorders such as infection, malignancy, medication, neurological, or endocrine diseases (2). While axillary hyperhidrosis is quite common with a prevalence of about 1.4 % (3), hyperhidrosis on the body unilaterally or lesionally is very rare. It has been termed localised unilateral hyperhidrosis (LUH) (4) and has been associated with organic disorders such as malignancies (5) or neurological disorders (6), but it has also been reported after a trauma (4) or as idiopathic (7).