Palmoplantar hyperhidrosis is a therapeutic challenge; options generally include topical and systemic agents, botulinum toxin type A injections, iontophoresis, with surgical sympathectomy as a last resort. However, all of these treatments come with their own associated complications and limitations.
The human body comprises of about 4 million sweat glands, of which eccrine comprises a massive 75%. The eccrine sweat glands are epidermal appendages that are innervated by cholinergic fibers of the sympathetic nervous system. Its major role is the production of sweat, which is colorless, odorless and responsible for maintenance and regulation of the body temperature. Their presence can be found throughout the body surface, dominatingly in the palmar, plantar, craniofacial and axillary regions.
Sudorrhea or polyhidrosis, commonly known as “hyperhidrosis” is a condition characterized by abnormally profuse perspiration. This phenomenon can affect either a specific area or the whole body. Though not life threatening, hyperhidrosis can be uncomfortable, causing embarrassment and psychological trauma in many. Palmoplantar hyperhidrosis is particularly associated with excessive sweating from the palms and soles, affecting both adults and children. Diagnosis of this socially disabling and potentially embarrassing condition depends on the patient's set of experiences and noticeable indications of perspiration. The condition is mostly idiopathic. Approximately 3% of the population are affected by palmoplantar hyperhidrosis, inflicting a significant impact on the quality of life.
The characteristic chronic excessive sweating in this disorder is unrelated to the need for heat loss of the body, therefore it happens in every season, including winters. Worsening of symptoms is noticed in situations of stress, fear, nervousness and anxiety. Although it affects both men and women, there prevails a false dominance of predominance in females because of the increased demand of treatment by women. Clinical recognition of this symptom usually occurs till third decade of life.
Palmoplantar hyperhidrosis exerts a huge impact on patient’s quality of life, interfering with their work, social interaction, daily activities and leisure, and can cause physiological and emotional distress. The natural history of palmoplantar hyperhidrosis is the beginning of profuse perspiration in childhood for most people, showing itself even more strongly in times of sexual and hormonal maturation during adolescence. Improvement is commonly seen after the fourth decade of life, and rare cases persist even after the fifth decade.
The condition is characterized by cold and wet palms and soles of the feet that present color ranging from pale to blush. This episode of excessive sweating has an abrupt onset which may or may not be related to stressful and emotional events, presenting with more intensity on the fingers and palms and comparatively less intensely in the posterior part of the hands. This results in wetting of the palms by droplet detachment, in some cases followed by swelling of the fingers.
• Topical Therapy
20 percent aluminum chloride hexahydrate in absolute anhydrous ethyl alcohol, commonly called drysol, is supposed to be one of the most effective topical treatments for palmoplantar hyperhidrosis. Other topical agents such as anticholinergic drugs, boric acid, 2-5% solutions of tannic acid, boric acid, formaldehyde, methenamine etc. provide less satisfactory results. Aluminum chloride obstructs sweat pores and induces atrophy of secretory cells within sweat glands. Documented hypersensitivity is the only contradiction documented in this treatment. Care should be taken to not use it on broken, recently shaven or irritated skin.
• Systemic Therapy
Previously, systemic anticholinergic medications have been, to some degree effective in the treatment of palmoplantar hyperhidrosis, in light of the activity of acetylcholine as the periglandular neurotransmitter within the sympathetic innervation of sweat glands. Long-term treatment is required, and the medications have various side-effects, including dry mouth, constipation, dry eyes, blurred vision, mydriasis and trouble with urination. Benzodiazepines can lessen anxiety levels, therefore diminishing the emotional stimuli responsible for triggering hyperhidrosis.
Passing a direct electrical current onto the skin, known as iontophoresis, has been a long-established therapy for the treatment of hyperhidrosis. For the successful induction of palmoplantar hyperhidrosis via tap-water iontophoresis, 15-20 mA is applied to each palm or sole for a duration of 30 minutes per session for almost 10 consecutive days. It is followed by a single or double maintenance session every week.
• Botulinum Toxin Type A
Botulinum toxin type A injections (Botox) are effective and safe and also improve the quality of life in patients with palmoplantar hyperhidrosis.
• Surgical Treatment
Since 1920s, sympathectomy has been performed in patients with disabling, recalcitrant hyperhidrosis. The procedure is mostly quite effective, but also permanent. Therefore, this should be considered as a last resort after the exhaustion of all other therapeutic options.