The often embarrassing, excessive sweating disorder, hyperhidrosis, and its treatment options are gaining greater attention from physicians. This is improving the efficacy of treatment and minimizing its adverse effects, Mayo Clinic authors write in the May issue of Mayo Clinic Proceedings.

Hyperhidrosis is one of the oldest known dermatologic conditions that even today is misconceived as rare and untreatable, says John Eisenach, M.D., a Mayo Clinic anesthesiologist and the primary author of the clinical review.

"Both ancient and modern medicine have been perplexed by this entity," says Dr. Eisenach.

The description and definition of excessive sweating date back to Hippocrates in the 4th century B.C. Today, the diagnosis and treatment of severe cases command a stepwise, multidisciplinary approach from the primary care physician, the dermatologist, the neurologist, and the surgeon. Variables include the site affected, the degree of severity and the response to treatment.

Dr. Eisenach and colleagues outline their findings on the evolving therapies and how this disorder is not as rare as commonly thought. "I think we've all shaken hands with someone who is affected by this," he says. "I just hope people with this condition seek help, because of the emerging treatment options and high satisfaction rates that can be obtained, even in severe cases."

The Food and Drug Administration approval of botulinum toxin type A (Botox) has provided an effective treatment of excessive sweating, particularly for the underarms. Other treatments may be utilized for excessive sweating on the face, the palms, or soles of the feet. A recent survey suggests that the prevalence of primary hyperhidrosis is 2.8 percent in the U.S. population, 1.4 percent have excessive sweating in the underarms (axillary hyperhidrosis), and one-sixth are projected to have sweating that is intolerable or interferes with daily activities. There also is a hereditary component, as approximately half of these patients have a relative with hyperhidrosis, says Dr. Eisenach.

Dr. Eisenach says one part of the brain controls the sweating response to body temperature, while another area controls the sympathetic, or emotional sweating response. For reasons unclear to hyperhidrosis researchers, the emotional component is in overdrive. The result is typically a healthy individual who perspires excessively, even in mildly stressful situations, such as a handshake or job interview. This can have socially debilitating consequences, particularly in young adults, Dr. Eisenach notes.

Not all sweating is benign, however. Primary hyperhidrosis affects people while they are awake, but nighttime sweating is never normal. A careful history and physical examination must be performed to rule out other causes of excessive sweating, which physicians call secondary hyperhidrosis. In contrast to the primary form, secondary hyperhidrosis is associated with other potentially serious medical problems that need further workup from physicians.

Treatment options are based on the severity of hyperhidrosis and the risks and benefits of therapy. They can range from antiperspirants to surgery, which involves disconnection of the sympathetic nerves that direct sweating in the arms and hands.

"Mayo Clinic's surgeons frequently perform these procedures for severe over-sweating of the hands when other treatments have failed," says Dr. Eisenach. "From an integrative standpoint, we are interested in studying the long-term effects of this surgery on the skin and blood vessels of the arm. So far, we have found essentially no adverse consequence in the patients' warm and dry hands."

Dr. Eisenach says Mayo researchers continue to gain insight into how this condition affects the body, before and after surgical correction. It also increases physicians' understanding of the sympathetic nervous system, also known as the "fight or flight response."