Genetic disposition to primary hyperhidrosis: a review of literature

Cluster Analysis Identifies Clinical Phenotypes of Primary Hyperhidrosis

INTRODUCTION

Identifying subgroups of patients with primary hyperhidrosis (PHH) can improve the understanding of the disease pathophysiology. The study objective was to determine the naturally occurring subgroups of patients with PHH based on clinical characteristics.

METHODS

In this retrospective cohort study, data were collected from participants included in a clinical trial. The data were collected between January 2020 and June 2021 from outpatients with PHH attending a dermatologic department in Denmark. Overall, 84 patients with PHH were screened for inclusion in the clinical trial. Of these, 41 met the eligibility criteria. Four participants were excluded because of missing data. The main outcome was the identification of subgroups of patients with PHH using an unsupervised hierarchical cluster analysis.

RESULTS

Overall, 37 patients were included {28 (76.7%) females; median age at inclusion 28.0 (interquartile range [IQR] 24.0-38.3); median body mass index 24.9 (IQR 20.9-27.4); median age of onset 13.0 (IQR 9.5-18.5); and 26 (70.3%) had a familial disposition toward PHH}. Two clusters of 18 and 17 patients were identified. The first cluster had, when compared to the second, a younger age of onset (median age 11.0 [IQR 0-13.0] vs. 17.0 [IQR 15.0-21.0], p = 0.003) and higher sweat rates on gravimetry (median 175.0 [IQR 121.2-252.5] vs. 40.0 [IQR 20.0-60.0] milligrams of sweat/5 min, p < 0.001) and transepidermal water loss (median 93.7 [IQR 91.2-97.8] vs. 59.0 [IQR 44.4-73.2] g/m2/h, p < 0.001). No differences were observed for the other variables.

CONCLUSIONS

This study identifies 2 subgroups of patients with PHH. The patients with an onset of PHH during childhood had a substantially higher sweat and evaporation rate in adulthood than those with an onset during adolescence. These findings may imply a changed understanding of the pathophysiology of PHH, by indicating that an early disease onset can lead to a worse disease course.

Treatment of Primary Axillary Hyperhidrosis with Two Doses of Botulinum Toxin A-Observational Study

Hyperhidrosis (HH) is defined as the production of more sweat than is necessary for its thermoregulatory function, negatively affecting patients' quality of life and interfering with their social, work and family life. In this context, the aim of thisstudy was to evaluate the efficacy of two different doses of botulinum toxin type A (50 or 100 units) in each axilla in severe primary axillary hyperhidrosis. A descriptive, observational, cross-sectional and post-authorisation study was conducted onpatients referred to our department.Thirty-one patients with severe primary axillary hyperhidrosis were included, some of whom received more than one infiltration during the follow-up period, performing a total of 82 procedures. They were assigned by simple random sampling to two types of treatment: infiltration of 50 or 100 units (U) of botulinum toxin A per axilla.Hyperhidrosis severity was assessed using the Hyperhidrosis Disease Severity Scale (HDSS), and quality of life was assessed using the Dermatology Life Quality Index (DLQI) questionnaire. Onabotulinum toxin A infiltration reduced the severity of hyperhidrosis and improved the quality of life of the treated patients, with no significant differences between the two groups.

Primary hyperhidrosis: From a genetics point of view

Primary hyperhidrosis is a disorder of profuse sweating which negatively influences a patient's quality of life and is caused because of over-activation of the sympathetic nervous system. It was believed that hyperhidrosis is a condition limited to only anxious individuals; however, this hypothesis is discredited now. It has been found that people with a positive family history of primary hyperhidrosis are likely to suffer from this condition, suggesting a strong genetic basis. Genetic analysis has revealed a dominant autosomal pattern of inheritance with a variable degree of penetrance and is a sex-independent trait. It is a heterogeneous condition both genetically and clinically as different studies revealed variable genetics and clinical factors. There are no proper criteria for diagnosis as it is not treated as disease by most affected persons. Various studies revealed opposing results in localizing disease gene loci, so further genetic research is needed to pinpoint genes responsible for causing this debilitating condition. Gene expression profiling of human anxiety-causing genes in hyperhidrotic sufferers will also help to devise new treatment modalities. This review highlights the current genetic studies on hyperhidrosis, which may prove to be helpful in understanding the molecular mechanism governing hyperhidrosis.

Patients' satisfaction after bilateral thoracoscopic sympathicolysis

Background

Palmar hyperhidrosis is a distressing condition implicating individuals' social life and self-esteem. Surgery has proven to be highly effective with excellent safety profile. However, compensatory hyperhidrosis (CH), a relatively common adverse event of the procedure, is sometimes problematic in a few patients.

Patients and Methods

A questionnaire, including Hyperhidrosis Disease Severity Scale (HDSS), was designed to assess the overall satisfaction of patients who underwent bilateral endoscopic thoracic sympathectomy between November 2018 and July 2021. They were requested to respond to the questionnaire before surgery and during the follow-up visits.

Results

Sixty-three patients were recruited, 37 males and 26 females. The age of the participants ranged from 6 to 27 years (mean 17.05 ± 5.55 years). Most patients reported a positive impact on their professional and social life. Two patients experienced significant compensatory hyperhydrosis impacting their daily life. There was a significant improvement of the HDSS score after surgery. Around 95.2% of the participants (n = 60) had three-point improvement indicating 80% reduction of sweat production.

Conclusion

: Bilateral endoscopic thoracoscopic sympathectomy has shown a high success rate with low adverse events. CH, however, remains a significant cause of morbidity in few patients. Therefore, continuous evaluation of patients' satisfaction is of utmost importance to help improve our understanding to risk factors and prevalence of CH, improve our techniques to minimise its occurrence and treat patients with distressing symptoms. These data will guide surgeons when counselling patients to make insightful decisions based on the benefits and risks of the procedure.

Treatment of hyperhidrosis with Botox (onabotulinumtoxinA): Development, insights, and impact

Hyperhidrosis (chronic excessive sweating) may substantially affect an individual's emotional and social well-being. Therapies available before onabotulinumtoxinA were generally topical, with limited effectiveness, application-site skin reactions, and frequent, time-consuming treatments. Intradermal injection of onabotulinumtoxinA to treat sweat glands arose as a novel therapeutic approach. To develop this treatment, appropriate dosing needed to be established, and training on administration was required. Further, no previous scale existed to measure the effects of hyperhidrosis on patients' lives, leading Allergan to develop and validate the 4-point Hyperhidrosis Disease Severity Scale (HDSS), which measures the disease's impact on daily activities. The onabotulinumtoxinA clinical development program for hyperhidrosis included 2 double-blind, placebo-controlled pivotal trials, immunogenicity studies, long-term studies of safety and efficacy, and quality of life assessments. In Europe and North America, the primary efficacy measures were, respectively, axillary sweat production measured gravimetrically and HDSS improvement. Compared with placebo, onabotulinumtoxinA treatment significantly reduced axillary sweat production and axillary hyperhidrosis severity, as measured by a 2-point or greater reduction on the HDSS. The effects of onabotulinumtoxinA occurred rapidly, within 1 week after injection, and lasted ≥6 months. Treatment with onabotulinumtoxinA was associated with significant quality of life improvements based on Short Form-12 physical and mental component scores. The Hyperhidrosis Impact Questionnaire also indicated greater treatment satisfaction, reduced negative impact on aspects of daily life, and improved emotional well-being with onabotulinumtoxinA versus placebo. The clinical development program and subsequent clinical experience showed that onabotulinumtoxinA treatment for hyperhidrosis was well tolerated with no new safety signals, and led to greater disease awareness.

Hyperhidrosis: A Central Nervous Dysfunction of Sweat Secretion

Hyperhidrosis (HH) is a central nervous dysfunction characterized by abnormally increased sweating due to a central dysregulation of sweat secretion. HH significantly affects the quality of life of patients in their private, social and professional environments. Physiologically, sweating is a mechanism that regulates body temperature, but it may also be triggered by emotional or gustatory stimuli. There are two main types of sweat glands: eccrine and apocrine glands. The central nervous system controls sweat secretion through the release of neurotransmitters into the autonomous nervous system (ANS) that activate the sweat glands. The hypothalamus has two separate neuronal pathways, one for thermoregulation and one for emotions. HH may thus be due to either a neuronal dysfunction of ANS regulation leading to a hyperactivity of the sympathetic nervous system, or to abnormal central processing of emotions. Crucially, there is no dysfunction of the sweat glands themselves. Various pathogenic mechanisms have been proposed to be involved in pathological sweat secretion in HH, ranging from structural changes within the ANS to increased expression of aquaporin 5 and upregulation of activin A receptor type 1 in eccrine sweat glands. Although a genetic predisposition has been demonstrated, it remains unclear exactly which genes are involved. To identify new, potential therapeutic targets and to improve treatment options, a good understanding of the signaling pathways involved, the underlying mechanisms, and the genetic components is essential. In this review we discuss the various aspects of sweat physiology and function that are necessary to explain pathological sweating. Our aim is to raise awareness of the complexity of HH to promote a better understanding of the disorder.

Hyperhidrosis and human leucocyte antigens in the Danish Blood Donor Study

Familial clustering of the skin disease primary hyperhidrosis suggests a genetic component to the disease. The human leucocyte antigen (HLA) is implicated in a range of diseases, including many comorbidities to hyperhidrosis. No study has investigated whether the HLA genes are involved in the pathogenesis of hyperhidrosis. We, therefore, compared HLA alleles in individuals with and without hyperhidrosis in this study of 65,000 blood donors. In this retrospective cohort study, we retrieved information on individuals with and without hyperhidrosis using self-reported questionnaires, the Danish National Patient Registry and the Danish National Prescription Registry on participants recruited to the Danish Blood Donor Study between 2010 and 2019. Association tests using logistic regression were conducted for each HLA allele corrected for sex, age, body mass index, smoking and principal components. Overall, 145 of 65,795 (0.2%) participants had hospital diagnosed hyperhidrosis. Similarly, 1,379 of 15,530 (8.9%) participants had moderate-severe self-reported hyperhidrosis, of whom 447 (2.9%) had severe self-reported hyperhidrosis. Altogether 28 participants had both hospital diagnosed and moderate-severe self-reported hyperhidrosis. Severe self-reported hyperhidrosis was associated with HLA-A*80:01 (adjusted odds ratio 26.97; 95% confidence interval 5.32-136.70; n=7; p<0.001). Moderate-severe self-reported hyperhidrosis and hospital diagnosed hyperhidrosis were not associated with any HLA. The association between hyperhidrosis and HLA-A*80:01 was based on a very small number of cases and not replicated in other patient subsets, and therefore likely a chance finding. Thus, this study suggests that genes other than the HLA are involved in the pathogenesis of hyperhidrosis.

Comparison of EQ-5D-3L and metabolic components between patients with hyperhidrosis and the general population: a propensity score matching analysis

PURPOSE

It is important to understand the characteristics of patients with hyperhidrosis, which are different from the general population, for treating hyperhidrosis. Sympathetic overactivity, which might play an important role in hyperhidrosis, can contribute to metabolic diseases and the decreased quality of life (QoL). We compared the metabolic components and health-related QoL between patients with hyperhidrosis and the general population.

METHODS

We conducted a case-control study and compared the characteristics of the patients (N = 196) with hyperhidrosis and propensity score-matched controls (N = 196) selected from the Korean National Health and Nutrition Examination Survey. Metabolic components and EQ-5D-3L (EQ-5D) index were compared using a two-way mixed analysis of covariance after adjusting for confounders.

RESULTS

Patients with hyperhidrosis had significantly higher waist circumference (estimated mean values ± SD for patients and the control group, 85.5  ±  10.8 cm vs 81.3  ±  10.3 cm, p < 0.001), blood pressure (SBP, 121.1  ±  16.9 vs 111.7  ±  10.3, p < 0.001 AND DBP, 77.5  ±  12.8 vs 73.6  ±  8.6, p < 0.001, respectively), fasting glucose (97.1  ±  11.3 vs 91.5  ±  9.2, p < 0.001), and the number of components of metabolic syndrome (1.4  ±  1.3 vs 1.0  ±  1.2, p = 0.002), and significantly lower estimated glomerular filtration rate (144.3  ±  53.2 vs 158.3  ±  55.7, p = 0.002) and EQ-5D values (estimated mean values (standard error) for patients and the control group, 0.92 (0.01) vs 0.97 (0.01), p < 0.001) compared to the control group after adjustment.

CONCLUSION

The patients with hyperhidrosis had more central obesity and unfavorable metabolic parameters and a lower EQ-5D index compared with the general population, emphasizing clinical importance of hyperhidrosis to be cured in aspect of metabolic components as well as patients' QOL.

[Hyperhidrosis from diagnosis to management]

Hyperhidrosis is defined as uncontrollable, excessive and unpredictable sweating that exceeds the needs related to thermoregulation. It preferentially affects axillary, palms, soles and face but can affect any part of the body. This ostensibly benign symptom can have a major negative impact on quality of life sometimes leading to isolation and depression. Moreover, in some cases hyperhidrosis can be secondary to an underlying pathology sometimes malignant which must be identified quickly. Consequently, each doctor should be able to develop a diagnostic and therapeutic approach for this relatively frequent and probably underdiagnosed and undertreated reason for consultation. In this review, we focus on diagnosis hyperhidrosis and its management.