Hyperhidrosis

Hyperhidrosis is a medical condition characterised by excessive sweating, beyond what is necessary for body temperature regulation. This condition, while benign, can significantly affect one's quality of life, leading to psychological, emotional, and social consequences. Individuals with hyperhidrosis often face professional difficulties, with over 80% experiencing moderate to severe emotional impacts and around half suffering from depression.

Classification

Hyperhidrosis can be classified based on its distribution and cause. It may be generalised, affecting the entire body, or localised to specific areas such as the hands, feet, underarms, and face. Localised hyperhidrosis is referred to as primary or focal hyperhidrosis, whereas generalised hyperhidrosis is termed secondary hyperhidrosis, often linked to underlying conditions. Primary hyperhidrosis usually begins in adolescence and is often inherited, whereas secondary hyperhidrosis can start later in life and can be associated with conditions like diabetes mellitus, Parkinson's disease, and hyperthyroidism.

Causes

Primary Hyperhidrosis

The exact cause of primary hyperhidrosis is unknown, but factors such as anxiety, certain foods, drinks, nicotine, caffeine, and smells can exacerbate it. Conditions associated with primary hyperhidrosis include idiopathic unilateral circumscribed hyperhidrosis and various syndromes like POEMS syndrome and burning feet syndrome.

Secondary Hyperhidrosis

Secondary hyperhidrosis can be caused by a variety of factors including certain cancers (e.g., lymphoma, pheochromocytoma), endocrine disorders (e.g., diabetes mellitus, hyperthyroidism), medications (e.g., SSRIs, tricyclic antidepressants), and other conditions like Parkinson's disease and anxiety. It can also be triggered by febrile diseases, vigorous exercise, and a hot, humid environment.

Diagnosis

Diagnosis of hyperhidrosis typically involves a physical examination by a dermatologist, focusing on areas of excessive sweating. Questions about the patient's medical history and specific triggers are asked to understand the condition better. In some cases, a sweat test is conducted, where a powder that turns purple upon contact with sweat is applied to the skin.

Treatment

Topical Agents

Antihydral cream and other topical agents such as formaldehyde lotion and topical anticholinergics are commonly used to treat hyperhidrosis. These agents work by occluding the pores of sweat glands but have short-lasting effects and potential side effects like skin irritation.

Medications

Oral anticholinergics, including propantheline, glycopyrronium bromide, and oxybutynin, are prescribed for both generalised and focal hyperhidrosis. However, side effects such as dry mouth, urinary retention, and visual disturbances can limit their use. For anxiety-induced hyperhidrosis, taking an anticholinergic before an anxiety-provoking event may be beneficial.

Procedures

Botulinum toxin type A (Botox) injections can block neural control of sweat glands, providing relief for 3–9 months. The injections, however, can be painful. Another promising treatment is miraDry, a microwave-based device for axillary hyperhidrosis, though it carries risks like upper limb paralysis.

Tap water iontophoresis, described in the 1950s, has shown positive results for palmoplantar hyperhidrosis, reducing sweating by approximately 80%.

Surgery

Surgical options include sweat gland removal or destruction and endoscopic thoracic sympathectomy (ETS). ETS, which involves cutting, burning, or clamping the thoracic ganglion, is effective for hand sweating but has side effects like compensatory sweating and potential nerve regeneration. Other side effects can include Horner's syndrome and gustatory sweating.

Prognosis

Hyperhidrosis can lead to physical issues such as cold, clammy hands, dehydration, and skin infections. Emotionally, it can cause stress and depression, affecting one's personal and professional life. Excessive sweating can interfere with routine activities, from gripping objects to wearing certain types of shoes. It can also pose challenges in certain careers, particularly those requiring precise manual tasks or exposure to heat.

Epidemiology

Hyperhidrosis affects approximately 2.8% of the U.S. population, equally distributed between men and women, and is most common in individuals aged 25–64 years. A significant percentage of sufferers have a family history of the condition, indicating a genetic predisposition. Research has identified a gene locus (14q11.2–q13) associated with primary palmar hyperhidrosis.

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Self-assessment MCQs (single best answer)

What is hyperhidrosis?

Which of the following is a common emotional impact of hyperhidrosis?

Primary hyperhidrosis usually begins in which stage of life?

Secondary hyperhidrosis is often associated with which of the following conditions?

Which treatment involves blocking neural control of sweat glands with injections?

What is a potential side effect of oral anticholinergics?

What does the term "endoscopic thoracic sympathectomy (ETS)" refer to?

Which is not a common trigger for primary hyperhidrosis?

Which device uses microwave energy to treat axillary hyperhidrosis?

Which gene locus is associated with primary palmar hyperhidrosis?