Sweating is the body's way of cooling itself and is a normal response to a hot environment or intense exercise. However, Hyperhidrosis (excessive sweatingunrelated to these conditions)--as sweat retention syndrome--can be a problem for some people. Those with constantly moist hands may feel uncomfortable shaking hands or touching, while others with sweaty armpits and feet may haveto contend with the unpleasant odor that results from the bacterial breakdownof sweat and cellular debris (bromhidrosis). People with hyperhidrosis oftenmust change their clothes at least once a day, and their shoes can be ruinedby the excess moisture. Hyperhidrosis may also contribute to such skin diseases as athlete's foot (tinea pedis) and contact dermatitis.
Sweat retention syndrome, or miliaria rubra, also known as prickly heat, is acommon disorder of the sweat glands.
The skin contains two types of glands: one produces oil and the other produces sweat. Sweat glands are coil-shaped and extend deep into the skin. They arecapable of plugging up at several different depths, producing four distinctskin rashes.
- Miliaria crystallina is the most superficial of the occlusions. At this level, only the thin upper layer of skin is effected. Little blisters of sweat that cannot escape to the surface form. A bad sunburn as itjust starts to blister can look exactly like this.
- Deeper plugging causes miliaria rubra as the sweat seeps into the living layers of skin, whereit irritates and itches.
- Miliaria pustulosais (a complication of miliaria rubra) when the sweat is infected with pyogenic bacteria and turns topus.
- Deeper still is miliaria profunda. The skin is dry, and goose bumps may or may not appear.
There are two requirements for each of these phases of sweat retention: hot enough weather to induce sweating, and failure of the sweat to reach the surface.
Conditions or situations that can trigger hyperhidrosis are varied. They include stressful situations, eating spicy foods, consuming alcohol, the presenceof underlying disorders (e.g. tuberculosis, malaria, lymphoma, and diabetes), menopause, hormonal imbalances, and the use of certain drugs. Physicians believe that hyperhidrosis can be linked to a breakdown in communication between the brain and the mechanisms that activate sweating. In addition, a geneticlink may also exist: about 40% of people with the condition have a family history of it.
The best evidence to date suggests that bacteria form the plugs in the sweatglands. These bacteria are probably normal inhabitants of the skin, and why they suddenly interfere with sweat flow is still not known.
Infants are more likely to get miliaria rubra than adults. All the sweat retention rashes are also more likely to occur in hot, humid weather.
Besides itching, these conditions prevent sweat from cooling the body, whichit is supposed to do by evaporating from the skin surface. Sweating is the most important cooling mechanism available in hot environments. If it does notwork effectively, the body can rapidly become too hot, with severe and even lethal consequences. Before entering this phase of heat stroke, there will bea period of heat exhaustion symptoms--dizziness, thirst, weakness--when the body is still effectively maintaining its temperature. Then the temperature rises, often rapidly, to 104-5° F (40° C) and beyond. This is an emergency of the first order, necessitating immediate and rapid cooling. The best method is immersion in ice water.
The condition of excessive sweating is diagnosed by patient report and a physical examination.
The rash and dry skin in hot weather associated with sweat retention syndromeare sufficient usually to diagnose this condition.
Most over-the-counter antiperspirants are not strong enough to effectively prevent hyperhidrosis. To treat the disorder, doctors usually prescribe 20% aluminum chloride hexahydrate solution (Drysol), which the patient applies at night to the affected areas that are then wrapped in a plastic film until morning. Drysol works by blocking the sweat pores. Formaldehyde- and glutaraldehyde-based solutions can also be prescribed; however, formaldehyde may trigger an allergic reaction and glutaraldehyde can stain the skin (for this reason itis primarily applied to the soles). Anticolinergic drugs may also be used. In addition, an electrical device that emits low-voltage current can be held against the skin to reduce sweating. These treatments are usually conducted ina doctor's office on a daily basis for several weeks, followed by weekly visits. Dermatologists also recommend that patients wear clothing made of natural or absorbent fabrics, avoid high-buttoned collars, use talc or cornstarch,and keep underarms shaved.
The only permanent cure for hyperhidrosis of the palms is a surgical procedure. To treat severe excessive sweating, a surgeon can remove a portion of thenerve near the top of the spine that controls palm sweat. However, not very many neurosurgeons in the United States will perform the procedure. Alternatively, it is possible to remove the sweat gland-bearing skin of the armpits, but this is a major procedure that may require skin grafts.
The rash of sweat retention syndrome itself may be treated with topical anti-pruritics (itch relievers). Preparations containing aloe, menthol, camphor, eucalyptus oil, and similar ingredients are available commercially. Even moreeffective, particularly for widespread itching in hot weather, are cool bathswith corn starch and/or oatmeal (about 0.5 lb [224 g] of each per bathtub-full).
Dermatologists can peel off the upper layers of skin using a special ultraviolet light. This will remove the plugs and restore sweating, but is not necessary in most cases.
Much more important, however, is to realize that the body cannot cool itselfadequately without sweating. Careful monitoring for symptoms of heat diseaseis important. If they appear, some decrease in the ambient temperature must be achieved by moving to the shade, taking a cool bath or shower or turning upthe air conditioner.
While hyperhidrosis cannot be cured without radical surgery, it can usually be controlled effectively.
The rash associated with sweat retention sayndrome disappears in a day with cooler temperatures, but the skin may not recover its ability to sweat for twoweeks--the time needed to replace the top layers of skin with new growth from below.
Experimental application of topical antiseptics like hexachlorophene almost completely prevented these rashes.