Management Options for Primary Hyperhidrosis

Primary hyperhidrosis, or excessive sweating, affects not only the health of the skin but also emotional, physical, and social well-being. Dripping wet hands or feet can restrict career choice and the ability to participate in activities that involve tools or instruments— from work to music to sports. It can create a fear of intimacy, low self esteem, and social isolation. A Mayo Clinic-funded study recently found that 50% of those with hyperhidrosis suffer from social anxiety.

Robert D. Fealey, MD, a neurologist at Mayo Clinic in Rochester, Minnesota, has treated patients with hyperhidrosis for more than 25 years. He notes that psychological distress often reverses with successful management of the symptoms. Although hyperhidrosis has only recently been recognized as a serious medical condition, the departments of dermatology, neurology, and neurosurgery at Mayo Clinic have a long history of working together to treat primary hyperhidrosis. Management includes surgical and nonsurgical options as well as objective measures of severity and anatomic distribution and, for severe cases, an improved surgical approach not found at other institutions.

Primary vs Secondary Hyperhidrosis
Excessive sweating in primary or essential hyperhidrosis is thought to originate in the anterior cingulated cortex in response to emotional stimuli and is not considered a malfunction of the thermoregulatory system. It occurs independent of other conditions.

Primary, focal palmar hyperhidrosis demonstrated via purple staining with alizarin.

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Ventilated capsule recording from a patient with severe palmar hyperhidrosis.

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Primary hyperhidrosis has a prevalence of 2.8% in the United States. It is estimated that as many as half of those affected are unaware that treatments exist and do not seek medical help. Primary hyperhidrosis is usually focal, affecting the eccrine sweat glands of the axillae, palms of the hands, soles of the feet, and, more rarely, the face. The condition usually begins in childhood or adolescence. It is often inherited; approximately one-third of patients report a family history.

Secondary hyperhidrosis is associated with disorders such as chronic infection, malignancy, neurologic and endocrine disorders, and spinal cord injury. Patients with secondary hyperhidrosis often experience "night sweats," whereas patients with primary hyperhidrosis sweat excessively only when awake.

Diagnosis
After the history and physical examination, various laboratory tests can confirm the diagnosis and document the anatomic site where sweating occurs. Among these is the Mayo Clinic thermoregulatory sweat test. A mixture of starch, alizarin red, and sodium carbonate is painted on the anterior body surface and the palms and feet. The mixture turns from yellow-orange to dark purple in response to sweat. Computer-generated pictures are obtained under normal and elevated temperatures. This test helps to document the severity as well as the symmetric distribution of the sweating, another feature of primary hyperhidrosis.

Measuring severity is a critical step in determining the best treatment options. Severe cases, for example, may warrant surgery. There are several subjective rating scales that measure the degree to which hyperhidrosis interferes with daily life. For more objective data, Dr Fealey designed a humidity detector in which probes on the skin record sweat output relative to changes in humidity at normal temperatures. Changes from baseline measures are recorded as the patient is put under gentle stress (eg, computing serial 7s). As he explains, sweat driven by the anterior cingulate is not produced in a steady flow, but rather comes in waves or pulses. The waveform recordings are used to determine severity as well as to monitor treatment outcomes.

Nonsurgical Management
Treatment typically begins with topical agents that block the sweat ducts. These include over-the counter and prescription antiperspirants applied to dry skin at night and washed off 6 to 8 hours later.

Anticholinergics are another option. They inhibit acetylcholine activity on sweat glands innervated by postganglionic nerves and can be applied topically or taken by mouth. Adverse effects may include dry mouth and eyes, blurred vision, and difficulty with urination.

Iontophoresis is often tried when topical agents fail. A battery-powered device drives a low-level electrical current through water-saturated wool pads to the affected areas. This technique alters the outer layers of the skin to prevent sweat from coming to the surface. Hands and feet are treated separately. Each site must be treated twice a day for up to 30 minutes for approximately 2 weeks. Treatment effects may last for several weeks but may not be more effective than antiperspirants.

Over the past 10 years, botulinum toxin (Botox), which blocks nerve endings from releasing acetylcholine, has been used. Dr Fealey states that, in his experience, the greatest value of botulinum toxin is in treating the axillae, but it can be injected into the hands and feet as well. Injections done with the patient under local anesthesia are repeated every 4 to 6 months. Botulinum toxin can be applied to the face (around the hairline) in low doses, but there is a risk of weakening the facial muscles. At Mayo Clinic, this type of botulinum toxin injection is administered by dermatologists.

Schematic drawing of sympathectomy vs sympathotomy.

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Sympathotomy
Neurosurgery is an option reserved for intractable palmar hyperhidrosis. The approach used throughout the United States is a sympathectomy. Available for more than 70 years, it involves removing most or all of the upper thoracic sympathetic chain. The second thoracic ganglion, the largest relay center of sympathetic neurons to the upper extremities, is always removed in sympathectomy.

Endoscopic techniques make it a minimally invasive procedure.Unfortunately, a common complication of sympathectomy, affecting 5% to 20% of patients, is excessive compensatory sweating in the trunk, groin, legs, or all these sites. In describing extreme cases of compensatory hyperhidrosis, John L. D. Atkinson, MD, a Mayo Clinic neurosurgeon, notes that patients may no longer need to use handkerchiefs 40 times a day to wipe their hands but instead need to change their slacks 6 times a day because of excess sweating in the groin and legs.

To overcome compensatory hyperhidrosis, Dr Atkinson pioneered a procedure, unique to Mayo, called an endoscopic transthoracic sympathotomy. The sympathetic chain leading to the brachial plexus is not entirely removed. Instead, the second thoracic ganglion is disconnected from the stellate ganglion. In a prospective study of 10 patients undergoing sympathotomy, Drs Atkinson and Fealey found the procedure effective in controlling hyperhidrosis without causing compensatory sweating. Dr Atkinson has now performed sympathotomies on more than 120 patients. None has had severe compensatory hyperhidrosis in normal, temperature controlled environments. A few have had truncal hyperhidrosis in hot temperatures or with vigorous exercise. In an ongoing investigation of a phenomenon never before studied, he and his colleagues have found that the procedure does not appear to affect sympathetic innervation to the heart to any notable degree. Thus, the results to date suggest that endurance exercise or training is not affected by sympathotomy.

A young, healthy patient with primary palmarplantar hyperhidrosis in resting conditions at room temperature, presurgery (above) and postsurgery.

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Dr Atkinson cautions that neither sympathectomy nor sympathotomy is a good option for facial hyperhidrosis alone because it may induce Horner syndrome and/or a chimera in which sweating and facial redness occur on only 1 side of the face. It is also not appropriate for plantar hyperhidrosis alone because reducing sympathetic innervation to the lower extremities has consequences for maintaining blood pressure and can cause severe orthostatic hypotension.

Drs Fealey and Atkinson agree that in severe cases, successful sympathotomy in which compensatory hyperhidrosis is avoided can change patients' lives well beyond dry hands.