Anhidrosis
Anhidrosis, an abnormal deficiency of sweat, can be classified as generalized (complete) or localized (partial). Generalized anhidrosis can lead to life-threatening impairment of thermoregulation. Localized anhidrosis rarely interferes with thermoregulation because it affects only a small percentage of the body’s eccrine (sweat) glands.
Anhidrosis results from neurologic and skin disorders; congenital, atrophic, or traumatic changes to sweat glands; and the use of certain drugs. Neurologic disorders disturb central or peripheral nervous pathways that normally activate sweating, causing retention of excess body heat and perspiration. The absence, obstruction, atrophy, or degeneration of sweat glands can produce anhidrosis at the skin surface, even if neurologic stimulation is normal. (See Eccrine dysfunction in anhidrosis.)
Anhidrosis may go unrecognized until significant heat or exertion fails to produce sweat. However, localized anhidrosis often provokes compensatory hyperhidrosis in the remaining functional sweat glands, which, in many cases, is the patient’s chief complaint.
Emergency interventions
If you detect anhidrosis in a patient whose skin feels hot and flushed, ask if the patient is also experiencing nausea, dizziness, palpitations, and substernal tightness. If he is, quickly take his rectal temperature and other vital signs, and assess his level of consciousness (LOC). If a rectal temperature higher than 102.2° F (39° C) is accompanied by tachycardia, tachypnea, altered blood pressure, and decreased LOC, suspect life-threatening anhidrotic asthenia (heatstroke). Start rapid cooling measures, such as placing the patient on a cooling blanket, and give I.V. fluid replacements. Continue these measures, and frequently check vital signs and neurologic status, until the patient’s temperature drops below 102° F (38.9° C). Then place him in an air-conditioned room.
History and physical examination
If anhidrosis is localized or the patient reports local hyperhidrosis or unexplained fever, take a brief history. Ask the patient to characterize his sweating during heat spells or strenuous activity. Does he usually sweat slightly or profusely? Ask about recent prolonged or extreme exposure to heat and about the onset of anhidrosis or hyperhidrosis. Obtain a complete medical history, focusing on neurologic disorders; skin disorders, such as psoriasis; autoimmune disorders such as scleroderma; systemic diseases that can cause peripheral neuropathies such as diabetes mellitus; and drug use.
Inspect skin color, texture, and turgor. If you detect any skin lesions, document their location, size, color, texture, and pattern.
Medical causes
Anhidrotic asthenia (heatstroke)
Heatstroke is a life-threatening disorder that causes acute, generalized anhidrosis. In early stages, the patient may still sweat and be rational, but his rectal temperature may already exceed 102.2° F (39° C). Associated signs and symptoms include severe headache and muscle cramps, which later disappear; fatigue; nausea and vomiting; dizziness; palpitations; substernal tightness; and elevated blood pressure followed by hypotension. Within minutes, anhidrosis and hot, flushed skin develop, accompanied by tachycardia, tachypnea, and confusion progressing to seizures or loss of consciousness.
Burns
Depending on their severity, burns may cause permanent anhidrosis in affected areas as well as blistering, edema, and increased pain or loss of sensation.
Cerebral lesions
Cerebral cortex and brain stem lesions may cause anhidrotic palms and soles along with various motor and sensory disturbances specific to the site of the lesions.
Horner’s syndrome
A supraclavicular spinal cord lesion affecting a cervical nerve produces unilateral facial anhidrosis with compensatory contralateral hyperhidrosis. Other findings include ipsilateral pupillary constriction and ptosis.
Miliaria crystallina
This usually innocuous form of miliaria causes anhidrosis and tiny, clear, fragile blisters, usually under the arms and breasts.
Miliaria profunda
If severe and extensive, this form of miliaria can progress to life-threatening anhidrotic asthenia. Typically, it produces localized anhidrosis with compensatory facial hyperhidrosis. Whitish papules appear mostly on the trunk but also on the extremities. Associated signs and symptoms include inguinal and axillary lymphadenopathy, weakness, shortness of breath, palpitations, and fever.
Miliaria rubra (prickly heat)
This common form of miliaria, which typically produces localized anhidrosis, rarely can progress to life-threatening anhidrotic asthenia if it becomes severe and extensive. Small, erythematous papules with centrally placed blisters appear on the trunk and neck and rarely on the face, palms, or soles. Pustules may also appear in extensive and chronic miliaria. Related symptoms include paroxysmal itching and paresthesia.
Peripheral neuropathy
In this disorder, anhidrosis commonly appears over the legs with compensatory hyperhidrosis over the head and neck. Associated findings mainly involve the extremities and include glossy red skin; paresthesia, hyperesthesia, or anesthesia in the hands and feet; diminished or absent deep tendon reflexes; flaccid paralysis and muscle wasting; footdrop; and burning pain.
Shy-Drager syndrome
Shy-Drager syndrome is a degenerative neurologic syndrome that causes ascending anhidrosis in the legs. Other signs and symptoms include severe orthostatic hypotension, loss of leg hair, impotence, constipation, urine retention or urinary urgency, decreased salivation and tearing, mydriasis, and impaired visual accommodation. Eventually, focal neurologic signs—such as leg tremors, incoordination, and muscle wasting and fasciculations—may appear.
Spinal cord lesions
Anhidrosis may occur symmetrically below the level of the lesion, with compensatory hyperhidrosis in adjacent areas. Other findings depend on the site and extent of the lesion but may include partial or total loss of motor and sensory function below the lesion as well as impaired cardiovascular and respiratory function.
Other causes
Drugs
Anticholinergics, such as atropine and scopolamine, can cause generalized anhidrosis.
Special considerations
Because even a careful evaluation can be inconclusive, you may need to administer specific tests to evaluate anhidrosis. These include wrapping the patient in an electric blanket or placing him in a heated box to observe the skin for sweat patterns, applying a topical agent to detect sweat on the skin, and administering a systemic cholinergic drug to stimulate sweating.
Pediatric pointers
In both infants and children, miliaria rubra and congenital skin disorders, such as ichthyosis and anhidrotic ectodermal dysplasia, are the most common causes of anhidrosis.
Because delayed development of the thermoregulatory center renders an infant—especially a premature one—anhidrotic for several weeks after birth, caution parents against overdressing their infant.
Patient counseling
Advise the patient with anhidrosis to remain in cool environments, to move slowly during warm weather, and to avoid strenuous exercise and hot foods. Warn him about the anhidrotic effects of any drugs he’s receiving.
Pictures
Book Source Details
- Book Title: Professional Guide to Signs & Symptoms (Fifth Edition)
- Author(s): Springhouse
- Year of Publication: 2006
- Copyright Details: Professional Guide to Signs & Symptoms (Fifth Edition), Copyright © 2006 Lippincott Williams & Wilkins.
Other Book Chapters Related to Night sweats
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Medical Books Excerpts
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- "Handbook of Signs & Symptoms (Third Edition)" (2006)
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- Skin, clammy
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- "The 10-Minute Diagnosis Manual: Symptoms and Signs in the Time-Limited Encounter" (2000)
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- "Alarming Signs and Symptoms: Lippincott Manual of Nursing Practice Series" (2007)
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- Skin, clammy
- "Alarming Signs and Symptoms: Lippincott Manual of Nursing Practice Series" (2007)
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- "Signs & Symptoms: A 2-in-1 Reference for Nurses" (2007)
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- Diaphoresis
- "Signs & Symptoms: A 2-in-1 Reference for Nurses" (2007)
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- Sweating
- "The Diagnostic Approach to Symptoms and Signs in Pediatrics" (2006)
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Copyright Details: Professional Guide to Signs & Symptoms (Fifth Edition), Copyright © 2008 Williams & Wilkins.
More About Causes of Night sweats
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Diaphoresis (Professional Guide to Signs & Symptoms (Fifth Edition))
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