(See also Introduction to Sweating Disorders Introduction to Sweating Disorders There are two types of sweat glands: apocrine and eccrine. Apocrine glands are clustered in the axillae, areolae, genitals, and anus; modified apocrine glands are found in the external auditory... read more .)
Etiology of Hyperhidrosis
Hyperhidrosis can be focal or generalized.
Focal sweating
Emotional causes are common, causing sweating on the palms, soles, axillae, and forehead at times of anxiety, excitement, anger, or fear. It may be due to a generalized, stress-increased sympathetic outflow. Sweating is also common during exercise and in hot environments. Although such sweating is a normal response, patients with hyperhidrosis sweat excessively and under conditions that do not cause sweating in most people.
Gustatory sweating (sweating in response to or in anticipation of eating) can result from a number of causes; however, most often the cause is unknown. For example, sweating around the lips and mouth can occur when ingesting foods and beverages that are spicy or hot in temperature.
Pathologic causes include diabetic neuropathy Diabetic Neuropathy In patients with diabetes mellitus, years of poorly controlled hyperglycemia lead to multiple, primarily vascular, complications that affect small vessels (microvascular), large vessels (macrovascular)... read more , facial herpes zoster Herpes Zoster Herpes zoster is infection that results when varicella-zoster virus reactivates from its latent state in a posterior dorsal root ganglion. Symptoms usually begin with pain along the affected... read more , cervical sympathetic ganglion invasion, central nervous system injury or disease, or parotid gland injury.
Frey syndrome is a neurologic condition due to injury to or around the parotid glands resulting from surgery, infection, or trauma. Frey syndrome disrupts the auriculotemporal nerve, with subsequent inappropriate regeneration of parotid parasympathetic fibers into sympathetic fibers innervating local sweat glands in skin where the injury took place (1 Etiology reference Hyperhidrosis is excessive sweating, which can be focal or diffuse and has multiple causes. Sweating of the axillae, palms, and soles is most often a normal response due to stress, exercise... read more ). As a result, the misplaced parasympathetic fibers (which normally cause salivation as a gustatory response) now instead trigger sympathetic fibers that cause (inappropriate) redness and sweating of the preauricular cheek.
Other causes of focal sweating include pretibial myxedema Hypothyroidism Hypothyroidism is thyroid hormone deficiency. Symptoms include cold intolerance, fatigue, and weight gain. Signs may include a typical facial appearance, hoarse slow speech, and dry skin. Diagnosis... read more (shins), hypertrophic osteoarthropathy (palms), blue rubber bleb nevus syndrome, and glomus tumor (over lesions).
Compensatory sweating is intense sweating after sympathectomy.
Generalized sweating
Generalized sweating involves most of the body. Although most cases are idiopathic, numerous conditions can be involved (see table ).
Some Causes of Generalized Sweating
Etiology reference
1. Motz KM, Kim YJ. Auriculotemporal Syndrome (Frey Syndrome). Otolaryngol Clin North Am. 2016;49(2):501-509. doi:10.1016/j.otc.2015.10.010
Symptoms and Signs of Hyperhidrosis
Sweating is often present during examination and sometimes is extreme. Clothing can be soaked, and palms or soles may become macerated and fissured.
Palmar or plantar skin may appear pale.
Hyperhidrosis can cause emotional distress to patients and may lead to social withdrawal.
Diagnosis of Hyperhidrosis
History and examination
Iodine and starch test
Tests to identify a cause
Hyperhidrosis can be primary or secondary to an underlying medical condition. It is diagnosed by history and examination but can be confirmed with the iodine and starch test (1 Diagnosis reference Hyperhidrosis is excessive sweating, which can be focal or diffuse and has multiple causes. Sweating of the axillae, palms, and soles is most often a normal response due to stress, exercise... read more ). For this test, iodine solution is applied to the affected area and allowed to dry. Cornstarch is then dusted on the area, which makes areas of sweating appear dark. Testing is necessary only to confirm foci of sweating (as in Frey syndrome, or to locate the area needing surgical Surgery Hyperhidrosis is excessive sweating, which can be focal or diffuse and has multiple causes. Sweating of the axillae, palms, and soles is most often a normal response due to stress, exercise... read more or botulinum toxin treatment Botulinum toxin type A Hyperhidrosis is excessive sweating, which can be focal or diffuse and has multiple causes. Sweating of the axillae, palms, and soles is most often a normal response due to stress, exercise... read more ) or in a semiquantitative way when following the course of treatment. Asymmetry in the pattern of sweating suggests a neurologic cause.
Laboratory tests to identify a cause of hyperhidrosis are guided by the patient's other symptoms and might include, for example, complete blood count to detect leukemia Overview of Leukemia Leukemia is a malignant condition involving the excess production of immature or abnormal leukocytes, which eventually suppresses the production of normal blood cells and results in symptoms... read more , serum glucose to detect diabetes Diabetes Mellitus (DM) Diabetes mellitus is impaired insulin secretion and variable degrees of peripheral insulin resistance leading to hyperglycemia. Early symptoms are related to hyperglycemia and include polydipsia... read more , and thyroid-stimulating hormone to screen for thyroid dysfunction Overview of Thyroid Function The thyroid gland, located in the anterior neck just below the cricoid cartilage, consists of 2 lobes connected by an isthmus. Follicular cells in the gland produce the 2 main thyroid hormones... read more .
Diagnosis reference
International Hyperhidrosis Society: Diagnosis guidelines: Primary hyperhidrosis. Accessed March 29, 2024.
Treatment of Hyperhidrosis
Aluminum chloride hexahydrate solution
Topical anticholinergic medications
Oral anticholinergic medications
Oral clonidine
Botulinum toxin type A
Medical devices
Surgery
Initial treatment of focal and generalized sweating is similar. Various methods may be effective (1 Treatment references Hyperhidrosis is excessive sweating, which can be focal or diffuse and has multiple causes. Sweating of the axillae, palms, and soles is most often a normal response due to stress, exercise... read more ). Topical agents such as aluminum chloride hexahydrate solution and topical anticholinergic medications are usually considered first-line therapy because they are noninvasive and have few adverse effects.
(See also clinical guidelines from the International Hyperhidrosis Society.)
Aluminum chloride hexahydrate solution
Aluminum chloride hexahydrate (an antiperspirant) 6 to 20% solution in absolute ethyl alcohol is indicated for topical treatment of axillary, palmar, and plantar sweating; these preparations require a prescription. The solution precipitates salts, which block sweat ducts.
It is most effective when applied nightly and should be washed off in the morning. Sometimes an anticholinergic medication is taken before applying to prevent sweat from washing the aluminum chloride away.
Initially, several applications weekly are needed to achieve control, then a maintenance schedule of once or twice a week is followed. If treatment under occlusion is irritating, it should be tried without occlusion. This solution should not be applied to inflamed, broken, wet, or recently shaved skin.
High-concentration, water-based aluminum chloride solutions may provide adequate relief in milder cases.
Topical anticholinergic medications
Glycopyrronium tosylate 2.4% cloth wipes are used to treat primary axillary hyperhidrosis in people 9 years of age and older (2 Treatment references Hyperhidrosis is excessive sweating, which can be focal or diffuse and has multiple causes. Sweating of the axillae, palms, and soles is most often a normal response due to stress, exercise... read more ). Caution should be used in patients who are sensitive to the effects of anticholinergic medications.
Other topical anticholinergic options include glycopyrronium bromide, sofpironium bromide, and oxybutynin.
Oral anticholinergic medications
Glycopyrrolate or oxybutynin (3 Treatment references Hyperhidrosis is excessive sweating, which can be focal or diffuse and has multiple causes. Sweating of the axillae, palms, and soles is most often a normal response due to stress, exercise... read more ) can be used to decrease sweating but can be limited by anticholinergic adverse effects, including dry mouth, dry skin, flushing, blurred vision, urinary retention Urinary Retention Urinary retention is incomplete emptying of the bladder or cessation of urination. Urinary retention may be Acute Chronic Causes include impaired bladder contractility, bladder outlet obstruction... read more , mydriasis, and cardiac arrhythmias Overview of Arrhythmias The normal heart beats in a regular, coordinated way because electrical impulses generated and spread by myocytes with unique electrical properties trigger a sequence of organized myocardial... read more .
Clonidine
Oral clonidine is an alpha-2-adrenergic agonist that decreases sweating mediated by sympathetic nervous system activity.
Botulinum toxin type A
Botulinum toxin type A is a neurotoxin that decreases the release of acetylcholine from sympathetic nerves serving eccrine glands.
Injected directly into the axillae, palms, or forehead, botulinum toxin inhibits sweating for about 5 months depending on dose. The efficacy of botulinum toxin type A for hyperhidrosis is supported by data from randomized trials (4 Treatment references Hyperhidrosis is excessive sweating, which can be focal or diffuse and has multiple causes. Sweating of the axillae, palms, and soles is most often a normal response due to stress, exercise... read more , 5 Treatment references Hyperhidrosis is excessive sweating, which can be focal or diffuse and has multiple causes. Sweating of the axillae, palms, and soles is most often a normal response due to stress, exercise... read more ). Of note, in the United States botulinum toxin is approved only for axillary hyperhidrosis and may not be covered by insurance for other sites of hyperhidrosis.
Complications include local muscle weakness and headache. Injections are effective but painful and expensive, and treatment must be repeated 2 to 3 times per year.
Another consideration is botulinum toxin type A liposomal cream (6 Treatment references Hyperhidrosis is excessive sweating, which can be focal or diffuse and has multiple causes. Sweating of the axillae, palms, and soles is most often a normal response due to stress, exercise... read more ).
Medical devices
Tap-water iontophoresis, in which salt ions are introduced into the skin using electric current, is an option for patients unresponsive to topical treatments; however, supporting data are limited.
The affected areas (typically palms or soles) are placed in tap-water basins that each contain an electrode across which a 15- to 25-mA current is applied for 10 to 20 minutes. This routine is done daily for 1 week and then repeated weekly or bimonthly. Iontophoresis may be made more effective by dissolving anticholinergic tablets (eg, glycopyrrolate) into the basin water.
Although the treatments are usually effective, the technique is time-consuming and somewhat cumbersome, and some patients tire of the routine.
A microwave-based device can heat and subsequently permanently destroy sweat glands, resulting in efficacy over at least several months (7 Treatment references Hyperhidrosis is excessive sweating, which can be focal or diffuse and has multiple causes. Sweating of the axillae, palms, and soles is most often a normal response due to stress, exercise... read more ). Patients may benefit from 2 treatments at least 3 months apart.
Laser devices have been used to manage hyperhidrosis. These include diode laser, neodymium-doped yttrium aluminum garnet (Nd:YAG) laser, and fractionated microneedle radiofrequency devices (1 Treatment references Hyperhidrosis is excessive sweating, which can be focal or diffuse and has multiple causes. Sweating of the axillae, palms, and soles is most often a normal response due to stress, exercise... read more ). Laser-assisted delivery of botulinum toxin A solution with a fractionated CO2 laser can also be considered.
Surgery
Surgery is indicated if more conservative treatments fail.
Patients with axillary sweating can be treated with surgical excision of axillary sweat glands through open dissection or by liposuction (8 Treatment references Hyperhidrosis is excessive sweating, which can be focal or diffuse and has multiple causes. Sweating of the axillae, palms, and soles is most often a normal response due to stress, exercise... read more ); the latter appears to have lower morbidity.
Patients with palmar sweating can be treated with endoscopic transthoracic sympathectomy (9 Treatment references Hyperhidrosis is excessive sweating, which can be focal or diffuse and has multiple causes. Sweating of the axillae, palms, and soles is most often a normal response due to stress, exercise... read more ). The potential morbidity of surgery must be considered, especially in sympathectomy. Potential complications of sympathectomy include phantom sweating (a sensation of sweating in the absence of sweating), compensatory hyperhidrosis (increased sweating in untreated parts of the body), gustatory sweating, neuralgia, and Horner syndrome Horner Syndrome Horner syndrome is ptosis, miosis, and anhidrosis due to dysfunction of cervical sympathetic output. (See also Overview of the Autonomic Nervous System.) Horner syndrome results when the cervical... read more . Compensatory hyperhidrosis is most common after endoscopic transthoracic sympathectomy, developing in up to 80% of patients (10 Treatment references Hyperhidrosis is excessive sweating, which can be focal or diffuse and has multiple causes. Sweating of the axillae, palms, and soles is most often a normal response due to stress, exercise... read more ), and can be disabling and far worse than the original problem.
Treatment references
1. Henning MAS, Bouazzi D, Jemec GBE: Treatment of Hyperhidrosis: An Update. Am J Clin Dermatol 23(5):635-646, 2022. doi: 10.1007/s40257-022-00707-x
2. Glaser DA, Hebert AA, Nast A, et al: Topical glycopyrronium tosylate for the treatment of primary axillary hyperhidrosis: Results from the ATMOS-1 and ATMOS-2 phase 3 randomized controlled trials. J Am Acad Dermatol pii:S0190-9622(18)32224-2, 2018. doi: 10.1016/j.jaad.2018.07.002
3. Wolosker N, de Campos JR, Kauffman P, Puech-Leao P. A randomized placebo-controlled trial of oxybutynin for the initial treatment of palmar and axillary hyperhidrosis. J Vasc Surg. 2012;55(6):1696-1700. doi:10.1016/j.jvs.2011.12.039
4. Heckmann M, Ceballos-Baumann AO, Plewig G; Hyperhidrosis Study Group. Botulinum toxin A for axillary hyperhidrosis (excessive sweating). N Engl J Med. 2001;344(7):488-493. doi:10.1056/NEJM200102153440704
5. Naumann M, Lowe NJ. Botulinum toxin type A in treatment of bilateral primary axillary hyperhidrosis: randomised, parallel group, double blind, placebo controlled trial. BMJ. 2001;323(7313):596-599. doi:10.1136/bmj.323.7313.596
6. Lueangarun S, Sermsilp C, Tempark T. Topical Botulinum Toxin Type A Liposomal Cream for Primary Axillary Hyperhidrosis: A Double-Blind, Randomized, Split-Site, Vehicle-Controlled Study. Dermatol Surg. 2018;44(8):1094-1101. doi:10.1097/DSS.0000000000001532
7. Glaser DA, Coleman WP 3rd, Fan LK, et al. A randomized, blinded clinical evaluation of a novel microwave device for treating axillary hyperhidrosis: the dermatologic reduction in underarm perspiration study. Dermatol Surg. 2012;38(2):185-191. doi:10.1111/j.1524-4725.2011.02250.x
8. Cerfolio RJ, De Campos JR, Bryant AS, et al. The Society of Thoracic Surgeons expert consensus for the surgical treatment of hyperhidrosis. Ann Thorac Surg. 2011;91(5):1642-1648. doi:10.1016/j.athoracsur.2011.01.105
9. Drott C, Göthberg G, Claes G. Endoscopic transthoracic sympathectomy: an efficient and safe method for the treatment of hyperhidrosis. J Am Acad Dermatol. 1995;33(1):78-81. doi:10.1016/0190-9622(95)90015-2
10. Gossot D, Galetta D, Pascal A, et al. Long-term results of endoscopic thoracic sympathectomy for upper limb hyperhidrosis. Ann Thorac Surg. 2003;75(4):1075-1079. doi:10.1016/s0003-4975(02)04657-x
Key Points
Hyperhidrosis can be focal or generalized.
Asymmetric hyperhidrosis suggests a neurologic cause.
Although generalized sweating is usually normal, consider cancer, infection, and endocrine disorders as directed by patient symptoms.
Obtain laboratory tests to determine systemic causes based on clinical findings.
Treat using aluminum chloride solutions, tap-water iontophoresis, oral or topical anticholinergic medications, oral clonidine, botulinum toxin, or a microwaved-based or laser device.
Consider surgical options in patients who do not respond to medications or device therapy; surgical options include excision of axillary sweat glands and endoscopic transthoracic sympathectomy for palmar sweating, which carries risk of significant adverse effects.
More Information
The following English-language resource may be useful. Please note that THE MANUAL is not responsible for the content of this resource.
International Hyperhidrosis Society: Clinical guidelines for the treatment of hyperhidrosis