Hyperhidrosis: A Central Nervous Dysfunction of Sweat Secretion

Incidence and Severity of Compensatory Hyperhidrosis Following Bilateral Sympathectomy

BACKGROUND

Primary hyperhidrosis is a condition caused by an excessive stimulation of sweat glands, leading to a decline in both quality of life and social wellbeing. Thoracic sympathectomy surgery provides a relief of the initial symptoms but poses a risk for developing compensatory hyperhidrosis (CH) in various degrees.

OBJECTIVE

The aim of this study was to assess the occurrence and characteristics of CH post-thoracic sympathectomy.

METHODS

A retrospective cohort study of patients who underwent video-assisted thoracic sympathectomy surgery at level T2-T3 between 2016 and 2022 was conducted. Patients' data were retrieved from medical records and through a telephone interview.

RESULTS

A total of 50 patients (32 males and 18 females) were operated on with a mean ± standard deviation (SD) age of 25.9 ± 7.4 years at the time of surgery for palmoplantar hyperhidrosis. Initial symptoms started in childhood at a mean ± SD age of 11.4 ± 3.3 years. Postoperatively, 39 patients (78%) developed CH, more prevalent in males (64.1%) compared to females (35.8%). This CH mainly affected the back and abdomen (100%), followed by the groin and thighs (28.2%), and, to a lesser extent, the craniofacial area (15.3%). Onset of symptoms occurred within 1 week after surgery in 71.7% of cases, with 71.7% reporting mild to moderate symptoms. CH was significantly associated with higher age at the time of surgery, smoking status, and a longer time lapse in the surgery operation (P value < 0.05).

CONCLUSIONS

Thoracic sympathectomy is an effective procedure with a high success rate. Despite a relatively higher occurrence of CH, most patients experience milder symptoms and express satisfaction, noting that their expectations were met following the surgery.

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.

Lowering blood pressure by exercise: investigating the effect of sweating

High blood pressure (hypertension), is a common medical condition, affecting millions of people and is associated with significant health risks. Exercise has been suggested to manage hypertension by inducing sweating and the corresponding loss of sodium and water from the body.Thus, a variety of epidemiological and clinical studies have been conducted to investigate the relationship between sweating and exercise-induced blood pressure reduction and its impacts on hypertension. The mechanisms underlying exercise-induced blood pressure reduction are complex and still not fully understood. However, several pathways have been suggested, including the loss of sodium and water through sweat, a decrease in peripheral resistance, and an improvement in endothelial function in the blood vessels. The decrease in sodium and water content in the body associated with sweating may result in a reduction in blood volume and thus a decrease in blood pressure. Moreover, the reduction in peripheral resistance is thought to be mediated by the activation of the nitric oxide synthase pathway and the release of vasodilators such as prostacyclin and bradykinin, which lead to vasodilation and, thus, a reduction in blood pressure. In conclusion, exercise-induced sweating and consequent sodium and water loss appear to be a reliable biological link to the blood pressure-reducing effects of exercise in hypertensive individuals. Additionally, the mechanisms underlying exercise-induced blood pressure reduction are complex and involve several biological pathways in the cardiovascular system. Therefore, understanding the role of sweat production in blood pressure management is important for developing effective exercise interventions to prevent and manage hypertension.

What do Hyperhidrosis Quality of Life Index (HidroQoL©) scores mean? Transferring science into practice by establishing a score banding system

BACKGROUND

The Hyperhidrosis Quality of Life Index (HidroQoL©) is a measure of quality of life (QoL) impacts in hyperhidrosis (HH).

OBJECTIVES

We aimed to establish score banding systems for the HidroQoL total score for specific contexts representing different severity/impact categories by using the Dermatology Life Quality Index (DLQI) and the Hyperhidrosis Disease Severity Scale (HDSS) as anchors, including data from 357 patients from a phase III clinical trial.

METHODS

We used the HDSS, the established DLQI score bands and two single items (items 5 and 7) of the DLQI as anchors for the creation of banding systems for the HidroQoL. These anchors were chosen via consensus among an expert group according to relevance to patient experience. Due to the distribution of the HDSS and the single DLQI item 7, receiver operating characteristic curves were computed in order to create an optimal cut-off value of the HidroQoL total score. For the DLQI banding system and the single DLQI item 5, we created a banding system for the HidroQoL based on the distribution of their different categories.

RESULTS

A score of 30 and greater is proposed as the cut-off value for sweating that 'always interferes in daily activities', based on the HDSS as anchor. In terms of overall skin QoL effects, score bands of 0-6, 7-18, 19-25, 26-32 and 33-36 represent 'no effect', 'small effect', 'moderate effect', 'very large effect' and 'extremely large effect' on the patient's life, respectively.

CONCLUSIONS

In this study, we propose different banding systems for four different contexts: skin-specific QoL (DLQI banding), HH severity (HDSS), working and studying (single DLQI item 7) and social and leisure activities (single DLQI item 5). These banding systems and cut-off values can be used in clinical research and practice to place the patients in different severity categories.

Assessing Botulinum Toxin Effectiveness and Quality of Life in Axillary Hyperhidrosis: A One-Year Prospective Study

This study hypothesized that botulinum toxin (Botox) therapy would sustainably reduce sweat production in axillary hyperhidrosis patients over one year and significantly improve various quality-of-life aspects, including psychological well-being, social interactions, and daily functioning. The objectives were to quantitatively measure changes in sweat production and qualitatively assess the evolving impact on patients' quality of life over one year. Conducted prospectively at the Pius Brinzeu Clinical Emergency Hospital in Timisoara, Romania, this study complied with ethical standards and included adults with primary axillary hyperhidrosis unresponsive to conventional treatments. Participants underwent Botox injections and were evaluated at baseline, six months, and one year, using the Hyperhidrosis Disease Severity Scale (HDSS), WHOQOL-BREF, and the Dermatology Life Quality Index (DLQI), among other tools. Involving 81 patients, the study showed significant improvements in sweat production and quality-of-life metrics. Sweat production decreased from 0.81 g to 0.23 g per 15 min over one year (p < 0.001). HDSS scores reduced from 3.4 to 1.5, indicating a decrease in symptom severity (p < 0.001). The DLQI total score, assessing life quality impact, notably dropped from 19.9 to 6.9 (p < 0.001). Quality-of-life domains also showed significant improvements, especially in the social (from 65.3 to 73.4, p < 0.001) and environmental aspects (from 68.0 to 72.1, p < 0.001). Higher HDSS and sweat production were significantly associated with a lower quality of life on the DLQI (B coefficients of -4.1 and -2.5, respectively). Botulinum toxin therapy proved effective in reducing sweat production and improving the quality of life in axillary hyperhidrosis patients over a one-year period. These improvements were statistically significant in both physical and psychosocial domains. The study highlights the potential long-term benefits of Botox therapy for hyperhidrosis.

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.

Molecular and Physiological Functions of PACAP in Sweat Secretion

Sweat plays a critical role in human body, including thermoregulation and the maintenance of the skin environment and health. Hyperhidrosis and anhidrosis are caused by abnormalities in sweat secretion, resulting in severe skin conditions (pruritus and erythema). Bioactive peptide and pituitary adenylate cyclase-activating polypeptide (PACAP) was isolated and identified to activate adenylate cyclase in pituitary cells. Recently, it was reported that PACAP increases sweat secretion via PAC1R in mice and promotes the translocation of AQP5 to the cell membrane through increasing intracellular [Ca²⁺] via PAC1R in NCL-SG3 cells. However, intracellular signaling mechanisms by PACAP are poorly clarified. Here, we used PAC1R knockout (KO) mice and wild-type (WT) mice to observe changes in AQP5 localization and gene expression in sweat glands by PACAP treatment. Immunohistochemistry revealed that PACAP promoted the translocation of AQP5 to the lumen side in the eccrine gland via PAC1R. Furthermore, PACAP up-regulated the expression of genes (Ptgs2, Kcnn2, Cacna1s) involved in sweat secretion in WT mice. Moreover, PACAP treatment was found to down-regulate the Chrna1 gene expression in PAC1R KO mice. These genes were found to be involved in multiple pathways related to sweating. Our data provide a solid basis for future research initiatives in order to develop new therapies to treat sweating disorders.