Primary hyperhidrosis is a rare disorder characterized by excessive sweating on the palms of the hands, the soles of the feet, in the armpits (axillary), in the groin area, and/or under the breasts. The exact cause of primary hyperhidrosis is not known. When excessive sweating occurs as part of some other disorder, it is said to be secondary hyperhidrosis, which is a more commonly encountered condition than is primary hyperhidrosis.
Signs & Symptoms
The symptoms of primary hyperhidrosis typically begin during childhood or puberty and may often, although not always, persist throughout a person’s life. Affected individuals may experience a heightened reaction to certain stimuli that can cause sweating such as anxiety, pain, exercise, tension, caffeine, and/or nicotine. Extreme sweating may occasionally occur all over the body (generalized) or it may be localized in the palms of the hands and the soles of the feet (palmar-plantar hyperhidrosis); the underarm area (axilla); the groin; and under the breasts.
The face may be affected in the form of persistent blushing accompanying the excessive sweating.
When the palms and soles are involved, the skin may develop an abnormal pink or bluish-white appearance. The skin may also become unusually soft (macerated), cracked, or scaly, particularly on the feet.
The exact cause of primary hyperhidrosis is not known. The symptoms of this disorder develop due to overactivity of certain sweat glands, and attacks may be precipitated by social and/or physical stress. Even if stress can be identified as the precipitating cause, the disorder does not appear to be the result of a psychiatric disturbance.
Recently, several papers have been published suggesting a genetic origin and transmission of the disorder as an autosomal dominant trait. However, the gene locus has not been identified.
Chromosomes, which are present in the nucleus of human cells, carry the genetic information for each individual. Human body cells normally have 46 chromosomes. Pairs of human chromosomes are numbered from 1 through 22 and the sex chromosomes are designated X and Y. Males have one X and one Y chromosome, and females have two X chromosomes. Each chromosome has a short arm designated “p” and a long arm designated “q”. Chromosomes are further subdivided into many bands that are numbered. For example, “chromosome 11p13” refers to band 13 on the short arm of chromosome 11. The numbered bands specify the location of the thousands of genes that are present on each chromosome.
Genetic diseases are determined by the combination of genes for a particular trait that are on the chromosomes received from the father and the mother. All individuals carry 4-5 abnormal genes. Parents who are close relatives (consanguineous) have a higher chance than unrelated parents to both carry the same abnormal gene, which increases the risk to have children with a recessive genetic disorder.
Dominant genetic disorders occur when only a single copy of an abnormal gene is necessary for the appearance of the disease. The abnormal gene can be inherited from either parent, or can be the result of a new mutation (gene change) in the affected individual. The risk of passing the abnormal gene from affected parent to offspring is 50% for each pregnancy regardless of the sex of the resulting child.
Affected Populations: Primary Hyperhidrosis is a rare disorder that affects males and females in equal numbers. The symptoms of this disorder usually begin during childhood or puberty. Many people with Primary Hyperhidrosis experience relief from the symptoms during adulthood without treatment or obvious reason for the remission.
Secondary Hyperhidrosis is a more common condition that occurs in association with a variety of other disorders. It is important to distinguish Primary Hyperhidrosis from other underlying disorders that can cause excessive sweating (Secondary Hyperhidrosis). These disorders may include impaired thyroid function, malfunction of the pituitary gland, infectious diseases, diabetes, tumors, gout, menopause, side effects of certain drugs, and/or excessive alcohol consumption.