Anhidrosis is the absence of sweating. It can affect small or large areas of the body and be caused by one or more factors. Statistics on prevalence are scant as people with mild cases may not be aware that they have the condition or may never report it.
Because they can't sweat (or can’t sweat enough), people with severe anhidrosis have trouble working and exercising in heat and can be in danger if they attempt strenuous activity in high temperatures. They are at high risk for heat-related illnesses such as heat exhaustion and heat stroke.
Poor sweating can occur as an isolated condition or as part of a group of symptoms associated with another disease. It can also occur after skin has been injured, because sweat glands are clogged or obstructed, as an inherited defect, or as a side effect of a medication.
For people who suffer from anhidrosis on small parts of their bodies, treatment is probably not necessary because sweat from other body areas can compensate. For those with large body areas affected, finding the cause will dictate appropriate treatment.
Factors that may lead to anhidrosis include (but are not limited to):
- Medications: In particular, antipsychotic medications may interfere with functioning of the sweat glands. Also, medications with anticholinergic properties and calcium-channel blockers may cause anhidrosis.
- An Inherited Condition: Rarely, someone may be born without sweat glands. For example, ectodermal dysplasia impacts the development of the skin, sweat glands, nails, teeth, and/or mucous membranes. Without sweat glands, there’s a high risk of hyperthermia in hot environments.
- Nerve Damage: Injuries to the nerves that help control the autonomic nervous system can interfere with the activity of sweat glands. Such nerve damage may be caused by a number of issues including gout, B-vitamin deficiency, diabetes, and alcoholism.
- Clogged Ducts: Skin diseases and conditions that block or clog sweat ducts (poral occlusion) are the most common causes of anhidrosis.
- Skin Injures: Injuries to the skin and sweat glands can also cause anhidrosis. Such injuries can occur due to third-degree burns from fire, chemicals or electricity, or from medication overdose or poisonings.
- Dehydration
- Heat Stroke
Treatment for anhidrosis depends on the cause. Many cases aren’t easily treated. Anhidrosis of a limited body area is usually not a problem, but anhidrosis over large portions of the body can dangerously limit ability to keep cool. In such instances it's important to prevent heat exhaustion, heat stroke, and dehydration.