Maria Isabel Romano Hyperhidrosis is a condition of excessive sweating marked by abnormal wetness, sweaty palms, excessive axillary sweating, gustatory-stimulated sweating, wet shoes, and offensive body odor. Most cases are idiopathic or primary in nature and only rarely indicate an underlying secondary pathologic condition.1–3 Perspiration is one of the body’s mechanisms for thermal regulation and fluid and electrolyte balance. The center for body temperature regulation is located in the hypothalamus. Cooling perspiration is under hypothalamic control, whereas emotional perspiration is under cerebral control.4 Sweat glands are located in the hypodermis of the skin. The eccrine duct opens directly onto the surface of the skin. Millions of sweat glands are located in the hypodermis throughout the body, with the largest concentration in the palms, soles, and axillae. Secretions from the eccrine glands function to cool the body. Neural control is anatomically sympathetic. However, sweating is subject to cholinergic control mediated by acetylcholine, not epinephrine.2 Overactivity of the thoracic sympathetic ganglion may be the underlying cause of non–medically related excessive sweating. The most common cause of generalized increased sweating is a decline in ovarian function. Changes in neurohumoral function lead to increased stimulation of the hypothalamic thermal regulatory center, leading to the hot flashes associated with menopause. Other factors include fever, underlying infection or malignant disease, peripheral neuropathy or surgical damage to the autonomic nervous system, thyrotoxicosis, Parkinson disease, a variety of medications (including insulin, meperidine, and pilocarpine), and alcohol abuse.2 The presentation of primary hyperhidrosis is excessive sweating unrelated to ambient heat or humidity. Areas most commonly affected include the palms, soles, and axillae, but the condition may involve any body surface or may take on a unilateral distribution. Concern about the social consequences of this disorder (and its resulting body odor) and embarrassment may create a barrier to intimate relationships or affect the patient’s choice of occupation. When the soles are involved, widespread fungal infections of the skin and nails are accompanied by foot odor. More generalized body sweating is associated with an underlying condition, whereas localized sweating confined to the palms, soles, and axillae is more often a response to anxiety or heat or is idiopathic. Episodic sweating may be associated with hypoglycemia. A history of medications, including oral hypoglycemic agents and selective serotonin reuptake inhibitors (SSRIs), and alcohol intake is an important consideration. Based on the history and presenting complaint, the health care provider should try to locate evidence of any underlying disease process. A complete history is taken and a thorough physical assessment is performed, searching for signs and symptoms of hyperthyroidism. Blood pressure should be measured to exclude high blood pressure associated with pheochromocytoma.2 Heat intolerance associated with sweating in the upper half of the body and absence of sweating in the lower half of the body is evidence of diabetic peripheral autonomic neuropathy.5 In assessing the patient with generalized sweating, the examiner should look for miliaria rubra, an abnormal blocking of the sweat ducts. In this condition, sweat is trapped in the stratum corneum, creating tiny, pinpoint, clear papules that with pressure rupture the sweat ducts, creating an erythematous maculopapular rash. Other associated presentations include dyshidrotic eczema. This is a simple eczema promoted by the retention of sweat in the stratum corneum. Thyroid and fasting blood glucose studies are indicated to exclude thyroid disease and diabetes. If night sweats are present, a purified protein derivative test or interferon-γ release assay (QuantiFERON-TB Gold In-Tube [QFT-GIT] test; T-SPOT) is necessary to exclude tuberculosis. For perimenopausal women with hyperhidrosis, tests for follicle-stimulating hormone and luteinizing hormone are recommended to document menopause and to provide reassurance to the patient. SSRIs may provoke night sweats. A different SSRI should be considered before the drug class is changed. The most common cause of excessive perspiration is a sympathetic-mediated response to stress. A careful history and examination will indicate the necessity to exclude hyperthyroidism with an ultrasensitive test for thyroid-stimulating hormone (TSH) and thyroxine (T4). A patient symptom diary of provoking factors, response to foods, body temperature, and amount and location of perspiration is a helpful adjunct in determining the cause of sweating. If infection or malignant disease is suspected, a thorough evaluation is mandated. A tuberculin skin test should be performed for those with complaints of night sweats. A fasting blood glucose study is performed to exclude diabetes mellitus. In women with variations in the length and amount of menses, a search for accompanying symptoms of vasomotor hot flashes and objective evidence of ovarian failure is necessary. Symptoms of sweating and flushing accompanied by marked hypertension require an evaluation for pheochromocytoma. Evidence of central nervous system disease or autonomic peripheral neuropathy warrants referral to a neurologist.
Hyperhidrosis
Definition and Epidemiology
Pathophysiology
Clinical Presentation
Physical Examination
Diagnostics and Differential Diagnosis
Hyperhidrosis
Chapter 57
