What is Anhidrosis?

Anhidrosis, also known as hypohidrosis, is a medical condition characterized by the body's inability to sweat properly. A potentially life-threatening condition, a sweating deficiency is difficult to diagnose and may be indicative of the existence of an underlying illness. Several conditions may contribute to the development of hypohidrosis, including nerve or skin damage, dehydration, and genetics. Treatment involves determining and alleviating the underlying condition causing the anhidrosis.

Hypohidrosis is a condition that results from trauma to the sweat glands which leads to impaired function. Common origins of trauma include damage to the autonomic nervous system, injury to the skin, and adverse effects resulting from the use of certain medications. Anhidrosis may be caused by other factors which may not be directly traumatic, including dehydration and genetics.

Individuals who have experienced nerve damage due to a secondary condition, such as alcoholism or diabetes, may develop anhidrosis as a symptom of a more serious condition. Those who have been diagnosed with a metabolic disorder such as Fabry's disease or Horner's syndrome may also demonstrate symptoms associated with a perspiration deficiency. Individuals, who have sustained trauma to their skin, such as with a severe burn, may develop an inability to sweat in the affected area. Certain prescription medications may also inhibit normal sweating, including the use of some blood pressure, psychiatric, and anti-nausea medications.

Some people can easily become dehydrated resulting in the depletion of bodily fluids. Dehydration may impair the body's ability to cool itself, as well as its ability to function normally. Commonly associated with illness or excessive exposure to heat, dehydration may also result from the use of certain medications or the consumption of alcohol.

If the development of hypohidrosis is genetic, the individual is generally born with sweat glands that do not function properly. In some cases, an underlying, inherited condition may impair perspiration. Hypohidrotic ectodermal dysplasia is a condition that affects the development of an individual’s sweat glands, and may lead to the individual having too few or none at all.

The most prominent symptom associated with this condition is obviously the lack of perspiration. Those affected on larger portions of their bodies may be at a greater risk for complications, such as heatstroke. A perspiration deficiency may occur in patches on the body, over a majority of the body, or in a particular area. An individual with anhidrosis may also be asymptomatic, or exhibit no symptoms, which may contribute to the development of complications.

Those with anhidrosis who become symptomatic may exhibit additional signs that include dizziness, muscle cramping, and a flushing, or redness, of the face and neck. Severe symptoms resulting in physical weakness, nausea, or an accelerated heart rate require immediate medical attention. Individuals of advanced age or those with certain medical conditions, such as diabetes, may be at an increased risk of developing anhidrosis.

There are a few tests used to confirm a diagnosis of hypohidrosis. A quantitative sudomotor axon reflex test (QSART) is a painless test that may be used to measure the amount of sweat produced in response to administered stimuli. To assess the distribution of an individual’s perspiration, a sweat imprint test may be used. A thermoregulatory sweat test involves the use of a powdery substance placed on the skin prior to the individual being subjected to higher temperatures to provoke perspiration. As the individual perspires, the powder changes color allowing an analysis of his or her perspiration pattern.

Treatments associated with hypohidrosis are generally administered in an effort to treat the underlying cause of the deficiency, or heat-related symptoms. Immediate treatment for excessive overheating may include moving the individual to a cooler environment, administering cool beverages, and misting the skin with cool water. Individuals who become severely overheated must immediately seek medical attention to prevent a worsening of symptoms. Complications associated with anhidrosis include heatstroke, cramping, and heat exhaustion.