Management of Primary Focal Hyperhidrosis: An Algorithmic Approach

Involvement of aquaporin 5 and Na-K-2Cl cotransporter 1 in the pathogenesis of primary focal hyperhidrosis: evidence from the primary sweat gland cell culture

People with primary focal hyperhidrosis (PFH) usually have an overactive sympathetic nervous system, which can activate the sweat glands through the chemical messenger of acetylcholine. The role of aquaporin 5 (AQP5) and Na-K-2Cl cotransporter 1 (NKCC1) in PFH is still unknown. The relative mRNA and protein levels of AQP5 and NKCC1 in the sweat gland tissues of three subtypes of patients with PFH (primary palmar hyperhidrosis, PPH; primary axillary hyperhidrosis, PAH; and primary craniofacial hyperhidrosis, PCH) were detected with real-time PCR (qPCR) and Western blot. Primary sweat gland cells from healthy controls (NPFH-SG) were incubated with different concentrations of acetylcholine, and the relative mRNA and protein expression of AQP5 and NKCC1 were also detected. NPFH-SG cells were also transfected with si-AQP5 or shNKCC1, and acetylcholine stimulation-induced calcium transients were assayed with Fluo-3 AM calcium assay. Upregulated AQP5 and NKCC1 expression were observed in sweat gland tissues, and AQP5 demonstrated a positive Pearson correlation with NKCC1 in patients with PPH (r = 0.66, P < 0.001), patients with PAH (r = 0.71, P < 0.001), and patients with PCH (r = 0.62, P < 0.001). Upregulated AQP5 and NKCC1 expression were also detected in primary sweat gland cells derived from three subtypes of patients with PFH when compared with primary sweat gland cells derived from healthy control. Acetylcholine stimulation could induce the upregulated AQP5 and NKCC1 expression in NPFH-SG cells, and AQP5 or NKCC1 inhibitions attenuated the calcium transients induced by acetylcholine stimulation in NPFH-SG cells. The dependence of ACh-stimulated calcium transients on AQP5 and NKCC1 expression may be involved in the development of PFH.NEW & NOTEWORTHY The dependence of ACh-stimulated calcium transients on AQP5 and Na-K-2Cl cotransporter 1 (NKCC1) expression may be involved in the development of primary focal hyperhidrosis (PFH).

Hyperhidrosis: A Review of Recent Advances in Treatment with Topical Anticholinergics

Background

Topical anticholinergics have been reported to be effective in managing hyperhidrosis (HH) given the recent approval of glycopyrronium tosylate.

Objective

This review aimed to examine the effectiveness of emerging topical anticholinergic treatments for HH and their associated adverse effects in comparison to current treatment options.

Methods

We conducted a search within the PubMed and Embase databases for current and emerging topical anticholinergic treatments for primary HH.

Results

The topical anticholinergics that have been recently investigated for use in HH include glycopyrrolate, oxybutynin, sofpironium bromide, and umeclidinium. The only agent currently FDA approved is glycopyrrolate.

Conclusion

Knowledge of topical anticholinergic treatment options is important for patient care when managing HH. This review shows that while available safety data thus far are limited, emerging topical anticholinergics pose minimal known human risks.

Botulinum Toxin Type A for Treatment of Forehead Hyperhidrosis: Multicenter Clinical Experience and Review from Literature

Among the forms of idiopathic hyperhidrosis, those involving the forehead have the greatest impact on patients’ quality of life, as symptoms are not very controllable and are difficult to mask for patients. Although the local injection therapy with Incobotulinum toxin type A (IncoBTX-A therapy) can be considered a rational treatment, data from the literature describing both efficacy and safety of the treatment over the long term are poor. The aim of this report is to describe the single-center experience of five patients seeking treatment, for forehead hyperhidrosis with IncoBTX-A. To evaluate the benefits, safety profile and duration of anhidrosis, patients were treated following a standardized procedure and then followed until clinical relapse. The amount of sweating was measured by gravimetric testing, the extension of hyperhidrosis area was measured through Minor’s iodine starch test, and response to the treatment was evaluated using the Hyperhidrosis Disease Severity Scale (HDSS) and the Dermatology Life Quality Index (DLQI). In all treated patients, a significant anhidrotic effect was observed 4 weeks after the treatment and lasted for approximately 36 weeks. The reduction in sweat production was associated with significant amelioration of symptoms and quality of life for all treated patients. No serious side effects occurred; one patient complained of a mild transient bilateral ptosis. Although further wider studies are required, our preliminary results seem to encourage the use of IncoBTX-A in forehead hyperhidrosis.

Hyperhidrosis treatments in hidradenitis suppurativa: A systematic review

Hyperhidrosis impairs quality of life (QOL) in hidradenitis suppurativa (HS) patients and may exacerbate HS. However, there is limited literature on whether hyperhidrosis treatments improve HS disease. To systematically review literature on efficacy and tolerability of hyperhidrosis treatments in HS patients. In May 2021, MEDLINE and EMBASE databases were systematically searched by two reviewers per PRISMA guidelines for articles on hyperhidrosis and HS. Sixteen articles met inclusion criteria (2 randomized controlled trials [RCTs], one case-control study, three cross-sectional studies, 10 case-studies/series), encompassing 252 HS patients across studies. They examined botulinum toxin A (BTX-A) (n = 6) and B (BTX-B) (n = 1), suction-curettage (n = 1), diode laser (n = 1), and microwave-based energy device (MED) (n = 3). Overall, BTX treatments improve HS severity, QOL, hyperhidrosis, and were well-tolerated. Suction-curettage did not improve disease. One HS patient tolerated diode laser well, with improvement in sweating and HS. One RCT studying MED was discontinued due to adverse events. Two studies reported MED-induced HS. BTX was overall helpful in HS patients, including in patients without concomitant hyperhidrosis. However, more prospective studies are needed to examine its utility in HS. There is potential harm of MEDs in HS. Most studies examining hyperhidrosis treatments in HS patients are low level of evidence. Larger RCTs should examine the efficacy and tolerability of hyperhidrosis treatments in HS.