Hyperhidrosis: Anatomy, Pathophysiology and Treatment with Emphasis on the Role of Botulinum Toxins

Abstract

Clinical features, anatomy and physiology of hyperhidrosis are presented with a review of the world literature on treatment. Level of drug efficacy is defined according to the guidelines of the American Academy of Neurology. Topical agents (glycopyrrolate and methylsulfate) are evidence level B (probably effective). Oral agents (oxybutynin and methantheline bromide) are also level B. In a total of 831 patients, 1 class I and 2 class II blinded studies showed level B efficacy of OnabotulinumtoxinA (A/Ona), while 1 class I and 1 class II study also demonstrated level B efficacy of AbobotulinumtoxinA (A/Abo) in axillary hyperhidrosis (AH), collectively depicting Level A evidence (established) for botulinumtoxinA (BoNT-A). In a comparator study, A/Ona and A/Inco toxins demonstrated comparable efficacy in AH. For IncobotulinumtoxinA (A/Inco) no placebo controlled studies exist; thus, efficacy is Level C (possibly effective) based solely on the aforementioned class II comparator study. For RimabotulinumtoxinB (B/Rima), one class III study has suggested Level U efficacy (insufficient data). In palmar hyperhidrosis (PH), there are 3 class II studies for A/Ona and 2 for A/Abo (individually and collectively level B for BoNT-A) and no blinded study for A/Inco (level U). For B/Rima the level of evidence is C (possibly effective) based on 1 class II study. Botulinum toxins (BoNT) provide a long lasting effect of 3–9 months after one injection session. Studies on BoNT-A iontophoresis are emerging (2 class II studies; level B); however, data on duration and frequency of application is inconsistent.

Botulinum neurotoxin dose-dependently inhibits release of neurosecretory vesicle-targeted luciferase from neuronal cells

“…When applied locally at very low doses, botulinum toxins of serotype A and B can be used as a therapeutic for a number of ailments including torticollis spasmodicus, blepharospasm, strabism, facial spasms or hyperhidrosis (Chen, 2012;Lakraj et al, 2013;Sesardic and Das, 2009). In recent years, however, the major area of application of botulinum toxin serotype A has been aesthetic medicine, in particular to remove facial wrinkles that result from the contraction of subcutaneous muscles (Chen, 2012).…”

Axillary hyperhidrosis: A review of the extent of the problem and treatment modalities

“…Hence it is believed that hyperhidrosis is due to abnormal central control of emotions. 8 Thermoregulatory sweating occurs during the day and night, whereas emotional sweating is restricted to the daytime. Emotional sweating is controlled by the anterior cingulate cortex, of the hypothalamus.…”

“…It needs to be administered by a skilled clinician and has to be repeated every 4e12 months. 1,8,23 Oral medication Rarely, the next step in treatment used is oral anticholenergics. However the use of these is limited due to known side effects such as a dry mouth, tachycardia and impaired concentration.…”

“…7 Hyperhidrosis occurs due to "autonomic neuronal dysfunction". 8 The sympathetic nerves run from the cerebral cortex to the hypothalamus, through the lateral horn of the spinal cord and to post ganglionic fibres. It is thought that the nerves supplying the palms, feet and axilla are controlled distinctly from nerves in other parts of the hypothalamus and receive no regulation by thermosensitive areas; these nerves are controlled mainly by emotional centres.…”

Oral Medications

“…4 Anticholinergic agents work by competitive inhibition of acetylcholine at the muscarinic receptor. Muscarinic receptors are present throughout the central and autonomic nervous system, accounting for widespread and varied side effects that can develop.…”