Anhidrosis (Lack of Sweat)

What is anhidrosis?

Anhidrosis is a condition in which you can’t sweat (perspire) normally in one or more areas of your body. Sweating helps remove heat from your body so you can cool down. If you can’t sweat, your body overheats, which can be dangerous and even life-threatening.

How common is anhidrosis?

It’s not known how many people have anhidrosis. Many people with mild cases may not notice they aren’t sweating or may not go to their healthcare providers.

What are the causes of anhidrosis?

If you have anhidrosis, your sweat glands do not work properly. There are many possible causes. Some people are born with the condition, others develop it later in life.

Other known causes of anhidrosis include:

• Skin damage from burns, radiation therapy, or pore-clogging diseases such as psoriasis.
• Damage to the sweat glands from surgery, trauma or scar formation.
• Nerve damage caused by diabetes, alcoholism, and Guillain-Barre syndrome.
• Inherited disorder of the metabolic system (Fabry disease).
• Connective tissue disorders, such as systemic sclerosis, systemic lupus erythematosus, Sjogren syndrome.
• Autonomic nervous system disorders, such as Ross syndrome, and Harlequin syndrome.
• Nerve conditions (neuropathies), such as diabetes-related neuropathy, paraneoplastic neuropathy, inherited neuropathy, amyloid neuropathy, lepromatous neuropathy.
• Central nervous system diseases and conditions, including multiple system atrophy, dementia with lewy bodies, Parkinson's disease, stroke and spinal cord disease.
• Excessive dehydration.

Many medications interfere with sweat gland function. Anticholinergic medications are the most common drug-related cause of anhidrosis. Examples of anticholinergics include glycopyrrolate (Cuvposa®, Robinul®), doxepin (Silenor®, Zonalon®), atropine (Atropen®), cyproheptadine and hyoscyamine (Levsin/SL®, Hyosyne®). Other drug classes and examples include:

• Tricyclic antidepressants (amitriptyline).
• Antihistamines (diphenhydramine [Benadryl®, Nytol®]).
• Bladder antispasmodics (oxybutynin [Ditropan XL], tolterodine [Detrol®]).
• Antipsychotics / antiemetics (chlorpromazine, clozapine [Clozaril®], quetiapine [Seroquel®]).
• Antiepileptics (topiramate [Topamax®], zonisamide [Zonegran®]).
• Antihypertensives (clonidine [Catapres®]).
• Opioids (fentanyl, morphine, hydrocodone, oxycodone).
• Neuromuscular paralytics (botulinum toxins).

What are signs and symptoms of anhidrosis?

Signs and symptoms of anhidrosis include:

• Little or no sweating
• Dizziness
• Flushing
• Muscle cramps
• Overall weakness
• Feeling hot and not able to cool off

You may lack the ability to sweat in specific areas of your body, or the lack of sweating may be all over. Another pattern of anhidrosis is lack of sweat or very little sweat in certain body areas, but heavy sweating in other body areas. This happens because your body is trying to make up for the lack of sweat in one or more other body areas. Usually this is not a dangerous situation because your body is still able to cool off.

What should I do if I experience symptoms of anhidrosis?

Make an appointment to see your healthcare provider. Talk about your inability to sweat and other symptoms you have.

If you experience these symptoms in a heated environment, get out of the heat immediately and move into a shaded area or indoors, preferably with air-conditioning. Loosen your clothes and, if possible, apply cool damp cloths to your body. Seek medical attention if your symptoms don’t get better as you cool down.

Are there serious complications that can result from anhidrosis?

Severe cases of anhidrosis, where most or all of your body doesn’t sweat, may result in serious heat-related illnesses including:

• Heat exhaustion: Signs and symptoms are weakness, nausea, rapid heartbeat after strenuous activity in hot weather. Treatments include moving to a cooler place, drinking water, applying cool compresses or taking a cool shower.
• Heatstroke: This is an extremely dangerous, life-threatening condition in which your body temperature rises to 103 degrees Fahrenheit or higher. Heatstroke can cause confusion, loss of consciousness, coma and even death. Call 911 or take the person to the hospital. Move into shade, remove unnecessary clothing and cool the person (use ice packs, sponge with cool water, apply cool wet towels, spray down their body with a hose).

How is anhidrosis diagnosed?

Your healthcare provider will ask you questions about your lack of ability to sweat. You may also be asked to undergo a sweat test. In this test, you are coated with a powder that changes color where you sweat. You are moved into a chamber to make you perspire to see which parts of your body sweat.

You may have a skin biopsy performed to look for nerve fiber damage to determine a possible cause of anhidrosis. You may have other tests to try to determine other underlying causes of your anhidrosis.

How is anhidrosis treated?

If the anhidrosis is caused by a medication, it may be reversible if you stop the medication. Do not stop your medication without speaking to your healthcare provider first. If a medical condition is causing your anhidrosis, that condition may be treatable. If no other medical cause is found, treatment for anhidrosis may be limited to avoiding situations where lack of sweating causes a health problem, such as heat-related illness.

Can anhidrosis be prevented?

Anhidrosis can’t be prevented but you can do things to keep yourself from overheating, including:

• Wear loose-fitting, light-colored clothes. Wear a wide-brimmed hat.
• Move to or stay in a cool (air conditioned) place or move into the shade.
• Take a cool shower or sit in a bath of cool water.
• Stay hydrated. Drink plenty of fluids, especially water or sports drinks. Don’t drink alcohol or caffeine-containing beverages (coffees, teas, colas, chocolate).
• Move slowly, don’t overexert, don’t do heavy exercise.
• Carry a water bottle with you everywhere you go. You can drink the water or, in an emergency, use it to cool your body off if you are outside and unable to move to a cooler place.

What can I expect if I have anhidrosis?

Anhidrosis is usually a life-long condition. However, your prognosis depends on if an underlying cause can be found and if the cause is treatable. Treating the underlying medical condition should improve anhidrosis. If your anhidrosis is caused by a medication, anhidrosis is usually reversible when that medication is discontinued.

The most important things you can do if you have a diagnosis of anhidrosis are to:

• Keep your body cool by staying in a cool environment.
• Don’t overexert.
• Take precautions when outside in warm climates (see prevention section).
• Learn the signs and symptoms of heat exhaustion and heat stroke and know what to do if they occur (see complications).

When should I see my healthcare provider?

See your healthcare provider:

• If you notice that you do not sweat at all or very little on hot days or during activities that normally would cause sweating.
• If you notice that you hardly sweat, sweat less than usual (hypohidrosis) or you don’t sweat at all.

Seek immediate medical attention if you develop signs or symptoms of heatstroke (see complications above).