Focal hyperhidrosis

Focal hyperhidrosis is a medical condition characterized by excessive, localized sweating in specific areas of the body, most commonly affecting the palms, soles, underarms, or face. This condition is distinct from generalized hyperhidrosis, which involves widespread sweating over the entire body. Focal hyperhidrosis often begins in childhood or adolescence and can persist throughout life, significantly impacting the quality of life and social interactions of those affected.

Causes

The exact cause of focal hyperhidrosis is not fully understood, but it is believed to be related to overactivity of the sympathetic nervous system, specifically the nerves that control sweating. Genetic factors may also play a role, as the condition often runs in families. Unlike generalized hyperhidrosis, focal hyperhidrosis is not usually associated with an underlying medical condition.

Symptoms

The primary symptom of focal hyperhidrosis is excessive sweating that occurs in localized areas without an apparent cause, such as high temperature or physical activity. The sweating can be so severe that it soaks through clothing or drips off the hands. This can interfere with daily activities, such as writing or handling objects, and can cause social embarrassment or anxiety.

Diagnosis

Diagnosis of focal hyperhidrosis typically involves a medical history and physical examination. The Minor's iodine-starch test may be used to visually confirm the presence of excessive sweating. During this test, an iodine solution is applied to the sweaty area, followed by starch powder. Areas of excessive sweating will turn dark blue. In some cases, additional tests may be performed to rule out other conditions that can cause excessive sweating.

Treatment

Treatment for focal hyperhidrosis aims to reduce sweating and improve quality of life. Options include:

• Antiperspirants: Over-the-counter or prescription-strength antiperspirants containing aluminum chloride can be effective for mild cases.
• Iontophoresis: A device that passes a mild electrical current through water and into the skin's surface to temporarily block sweat glands.
• Botox injections: Botulinum toxin injections can temporarily block the nerves that trigger sweating. This treatment is effective for underarm, hand, and facial sweating.
• Medications: Oral medications, such as anticholinergics, can reduce sweating but may have side effects.
• Surgery: In severe cases, surgical options such as sympathectomy may be considered. This procedure involves cutting or destroying the sympathetic nerves responsible for excessive sweating.

Prognosis

While focal hyperhidrosis is a chronic condition, the symptoms can be effectively managed with treatment. Many individuals experience significant improvements in their symptoms and quality of life with appropriate therapy.

Epidemiology

Focal hyperhidrosis is relatively common, affecting both males and females. It is estimated that about 2-3% of the population suffers from this condition, though many cases may go undiagnosed or unreported due to embarrassment or lack of awareness.

See also

• Hyperhidrosis
• Sympathetic nervous system
• Botulinum toxin
• Sympathectomy