Seasonal Variation and Meteorological Correlates of Botulinum Toxin Injections for Axillary Hyperhidrosis in Japan: A Retrospective Analysis

Cureus. 2025 May 12;17(5):e83996. doi: 10.7759/cureus.83996. eCollection 2025 May.

ABSTRACT

BACKGROUND: Primary axillary hyperhidrosis, characterized by excessive underarm sweating without an underlying medical condition, significantly impairs quality of life. While various treatments exist, botulinum toxin type A injections are widely used in Japan, especially for severe cases. Although increased sweating is commonly observed during warmer months, the relationship between treatment demand and meteorological factors remains unclear. This study aims to determine whether there are seasonal differences in the number of axillary hyperhidrosis injections in Japan and to investigate their relationship with meteorological conditions.

METHODS: A retrospective, descriptive analysis was conducted using the National Database of Health Insurance Claims and Specific Health Checkups of Japan (NDB) from fiscal years 2019 to 2022. Monthly injection data were correlated with meteorological variables (temperature, precipitation, solar radiation, wind speed, relative humidity, atmospheric pressure) obtained from the Japan Meteorological Agency. Seasonal differences were assessed using the Steel-Dwass test, and partial correlation analysis examined associations between meteorological factors and injection numbers.

RESULTS: The number of axillary hyperhidrosis injections peaked consistently in May and June each year, with significantly higher volumes in spring and summer compared to fall and winter (p<0.001). Partial correlation analysis revealed a strong positive correlation between all-day solar radiation and injection numbers (r=0.7193; p<0.0001), while temperature (r=-0.6052; p<0.0001) and wind speed (r=-0.441; p=0.0031) were negatively correlated. Relative humidity showed a moderate positive correlation (r=0.3626; p=0.0169). The seasonal peak preceded the hottest months, suggesting proactive treatment-seeking behavior.

CONCLUSIONS: Botulinum toxin injections for axillary hyperhidrosis in Japan display a reproducible seasonal pattern, with demand peaking in late spring and early summer. Solar radiation, rather than temperature alone, is most closely associated with treatment frequency, indicating that patients may seek care in anticipation of increased symptoms. These findings can inform healthcare resource planning and patient education to optimize the management of axillary hyperhidrosis.

PMID:40519391 | PMC:PMC12162388 | DOI:10.7759/cureus.83996

PAI1 regulating CHRNA1 contributes to primary focal hyperhidrosis: Clinical and experimental studies

Mol Ther Nucleic Acids. 2025 May 16;36(2):102566. doi: 10.1016/j.omtn.2025.102566. eCollection 2025 Jun 10.

ABSTRACT

Primary focal hyperhidrosis (PFH) is a debilitating condition characterized by localized excessive sweating, yet its underlying mechanisms remain poorly understood. In this study, sweat gland tissues from PFH patients (n = 204) and healthy controls (n = 60) were analyzed to assess the mRNA and protein levels of plasminogen activator inhibitor 1 (PAI-1) and nicotinic acetylcholine receptor alpha 1 subunit (CHRNA1) using RT-qPCR and western blotting. Primary sweat gland cells were isolated for in vitro experiments, and a pilocarpine-induced hyperhidrosis mouse model was established to evaluate the therapeutic effect of recombinant human PAI-1 (rhPAI-1). PFH patients showed significantly reduced PAI-1 expression and elevated CHRNA1 expression compared to controls (p < 0.01). Treatment with rhPAI-1 downregulated CHRNA1 and aquaporin 5 (AQP5) expression in sweat gland cells and decreased sweat secretion and serum acetylcholine levels in vivo. These results suggest that PAI-1 negatively regulates CHRNA1 and AQP5 expression, offering new insights into the molecular pathology of PFH and identifying PAI-1 as a potential therapeutic target for hyperhidrosis.

PMID:40503176 | PMC:PMC12155562 | DOI:10.1016/j.omtn.2025.102566

Efficacy and Safety of Botulinum Toxin Type A in Primary Axillary Hyperhidrosis: A Meta-analysis and Systematic Review

Aesthetic Plast Surg. 2025 Jun 11. doi: 10.1007/s00266-025-04909-6. Online ahead of print.

ABSTRACT

BACKGROUND: The clinical efficacy of botulinum toxin type A (BTX-A) injections for the treatment in primary axillary hyperhidrosis is a subject of ongoing debate. This study aims to consolidate and analyze the available evidence regarding the use of BTX-A as a therapeutic intervention for this conclusion.

METHOD: This study was conducted in accordance with PRISMA guidelines and registered with PROSPERO. We included RCTs on BTX-A injections for PAH, comparing it to placebo or other treatments. A comprehensive literature search was conducted in multiple databases up to May 2024. Out of identified articles, some underwent full-text review and were included in the qualitative and quantitative synthesis. Statistical analyses were done using RevMan5.4, and study quality was assessed with the Cochrane risk of bias tool. Subgroup and sensitivity analyses were also conducted.

RESULT: Twelve studies met our inclusion criteria (n = 904). BTX-A injection showed greater sweat reduction compared to placebo by gravimetric measurement (116.12 [92.68-139.57]; P < 0.05). BTX-A injection showed comparable sweat reduction to other treatments by gravimetric measurement (26.14 [- 26.8, 79.07]; P = 0.333) and HDSS (- 0.85 [- 1.20, 0.50], P = 0.413). The pain score of BTX-A injection is comparable to other treatments (- 0.41 [- 1.11, 0.29], P = 0.456). BTX-A injection exhibited fewer side effects compared to other treatments (0.18 [0.07, 0.43], P < 0.05).

CONCLUSION: In primary axillary hyperhidrosis, BTX-A injection significantly reduces sweat production compared with placebo, and there is no statistically significant difference compared with other treatments. BTX-A injection had less fewer side effects compared with other treatments.

LEVEL OF EVIDENCE I: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

PMID:40500510 | DOI:10.1007/s00266-025-04909-6

Primary Hyperhidrosis in Children: Current Perspectives and Therapeutic Options

Pediatr Ann. 2025 Jun;54(6):e196-e202. doi: 10.3928/19382359-20250321-03. Epub 2025 Jun 1.

ABSTRACT

Primary hyperhidrosis is a common condition that often begins before age 18 years and frequently presents to the pediatric primary care provider. It can have significant negative impacts on a child’s quality of life (QOL) and emotional well-being. There are a variety of treatment options available that have been shown to decrease symptoms, as well as improve QOL. These treatments include over-the-counter antiperspirants, prescription antiperspirants, topical anticholinergics, iontophoresis, systemic anticholinergics, injectable botulinum toxin, and surgical sympathectomy. Treatment of this condition is lifelong and often nuanced. It is imperative for the pediatric practitioner to be well versed in the risks and benefits, as well as proper usage, of these various therapeutic modalities. With this knowledge, effective treatment plans can be crafted to improve both the physical and mental health of affected children. [Pediatr Ann. 2025;54(6):e196-e202.].

PMID:40489364 | DOI:10.3928/19382359-20250321-03

Achieving high patient satisfaction after sympathectomy through preoperative thoracoscopic sympathetic nerve block in primary hyperhidrosis

J Thorac Dis. 2025 Apr 30;17(4):2050-2055. doi: 10.21037/jtd-2024-2145. Epub 2025 Apr 21.

ABSTRACT

BACKGROUND: Compensatory hyperhidrosis (CH) is a frequent complication following sympathectomy, influencing patient satisfaction. This study was established to evaluate the impact of bilateral thoracoscopic sympathetic nerve block (TSNB) on patient satisfaction after sympathectomy in the treatment of primary hyperhidrosis.

METHODS: From March 2021 to August 2023, 52 patients with primary palmar and craniofacial hyperhidrosis underwent TSNB at T3 using a 2-mm thoracoscope under local anesthesia. One week later, they decided whether to proceed with sympathectomy. Satisfaction was assessed using a 100-point scale, and patients were divided into two groups based on CH occurrence after sympathectomy. The groups were compared in terms of sex, age, hyperhidrosis site, and satisfaction scores.

RESULTS: Among 52 patients who underwent TSNB, 35 (67.31%) proceeded to sympathectomy, and CH occurred in 18 (51.43%) of these patients, while the remaining 17 patients (48.57%) did not develop CH. No significant differences were observed between the CH and no-CH groups regarding age (26.61±9.02 vs. 25.41±10.09 years, P=0.66), sex (61.11% vs. 52.94% male, P=0.88), or primary hyperhidrosis site (palmar: 77.78% vs. 88.24%, P=0.66). Satisfaction scores were comparable between the CH group (92.50±7.33) and the no-CH group (96.18±4.52), with no statistically significant difference (P=0.15).

CONCLUSIONS: Sympathectomy is associated with a high incidence of CH. Through TSNB, patients could preoperatively experience potential effects, including CH, enabling informed surgical decisions. Patients who developed CH reported high satisfaction levels comparable to those without CH, underscoring the utility of TSNB in improving patient-centered outcomes.

PMID:40400983 | PMC:PMC12090137 | DOI:10.21037/jtd-2024-2145

A Comparative Study of Aluminum Chloride, Oxybutynin Chloride, and Botulinum Toxin in the Treatment of Primary Focal Hyperhidrosis

J Cutan Med Surg. 2025 May 21:12034754251336233. doi: 10.1177/12034754251336233. Online ahead of print.

ABSTRACT

BACKGROUND: Primary hyperhidrosis (HH) is a common challenging problem. Different treatment modalities are present with no clear evidence favoring one modality over the others.

OBJECTIVES: To assess and compare the efficacy of aluminum chloride hexahydrate (ACH), oxybutynin chloride, and botulinum toxin type-A (BTX-A) in treating primary focal HH.

PATIENTS AND METHODS: Sixty-six patients of both sexes, with primary HH, were equally and randomly divided into 3 groups. Group (A) received a single session of intradermal (BTX-A), Group (B) received topical application of ACH lotion 25% once daily, and Group (C) received oral oxybutynin chloride 10 mg daily for 3 months. The clinical response was assessed using the Hyperhidrosis Severity Scale (HDSS) and the patients were followed up for 6 months.

RESULTS: The 3 modalities were effective and safe in the treatment of primary HH, but the clinical response was significantly higher in the BTX-A group (81.8% excellent response) compared to the other 2 modalities. The reduction of hyperhidrosis was also maintained for a longer period in the BTX-A group.

CONCLUSION: Among the 3 modalities, BTX-A was associated with a higher reduction of HDSS scores. A single session was sufficient; however, pain and high cost are limiting factors.

PMID:40396355 | DOI:10.1177/12034754251336233

Global research trends and hotspots of hyperhidrosis: a bibliometric analysis (2008-2023)

Front Surg. 2025 Apr 22;12:1559951. doi: 10.3389/fsurg.2025.1559951. eCollection 2025.

ABSTRACT

BACKGROUND: Recent studies have demonstrated significant advancements in the treatment of hyperhidrosis. However, a bibliometric analysis of relevant studies in this field is notably lacking. This study aims to provide a detailed analysis of research trends and key areas of interest in hyperhidrosis over the last 16 years using bibliometric methods.

METHODS: We searched the Web of Science Core Collection (WoSCC) database for hyperhidrosis-related publications from 2008 to 2023 and conducted bibliometric analysis using VOS viewer and the R package “bibliometrix.”

RESULTS: The main research institutions involved in this study are the University of São Paulo, Hospital Israelita Albert Einstein, Yonsei University and Fujian Medical University, with a total of 728 articles included from 52 countries. Authors from these institutions have published in top journals, with Dermatologic Surgery being the most popular journal and the Journal of the American Academy of Dermatology being the most cited. A total of 2,830 authors have contributed to this field, with prominent researchers including Nelson Wolosker, Paulo Kauffman, Pedro Puech-Leão, Jose Ribas Milanez de Campos, and Dee Anna Glaser. Nelson Wolosker stands out as the most co-cited author. The primary focus of research in this area is on the treatment of hyperhidrosis and the prevention of post-operative complications. Emerging re-search hotspots include keywords such as “botulinum toxin,” “oxybutynin,” “sympathectomy,” “iontophoresis,” and “compensatory sweating”.

CONCLUSION: The most prevalent academic emphasis within this field remains the treatment of hyperhidrosis and the management of compensatory hyperhidrosis. Despite this academic preponderance, there is a compelling necessity to foster enhanced collaboration and exchange between disparate countries and institutions.

PMID:40330089 | PMC:PMC12052815 | DOI:10.3389/fsurg.2025.1559951

Case Report: Single-port thoracoscopic surgery for severe primary palmar hyperhidrosis in a 9-year-old child

Front Med (Lausanne). 2025 Apr 15;12:1542064. doi: 10.3389/fmed.2025.1542064. eCollection 2025.

ABSTRACT

Primary palmar hyperhidrosis (PPH) is a somatic condition characterized by excessive sweating of the hands. It mainly affects adolescents and young adults and is rarely observed among children. This condition significantly impairs patients’ academic performance, daily activities, and social interactions and can even lead to insurmountable psychological burdens. Surgical intervention for PPH is typically reserved for individuals aged 16 years and older, as compensatory hyperhidrosis occurs at a high rate (65%) postoperatively among children younger than 14 years. Therefore, the decision for surgery is controversial and has been rarely documented in the literature. Here, we report a 9-year-old child with a 3-year history of bilateral palmar hyperhidrosis. Conservative treatment with medications for 6 months led to no improvement. The patient had signs of low self-esteem, social withdrawal, and aversion to school, alongside recurrent skin damage at the fingertips. Both the child and parents expressed a strong desire for effective treatment. Single-port endoscopic thoracic sympathectomy (ETS) was conducted after comprehensive risk disclosure and obtaining informed consent from the parents, achieving remarkable therapeutic outcomes. At the 12-month follow-up, the patient exhibited no recurrence of symptoms, no compensatory hyperhidrosis, and no complications, such as Horner’s syndrome. Both hands remained warm and dry, the lesions of fingertip skin healed, and the patient’s personality became noticeably more positive. Furthermore, the surgical incision was aesthetically pleasing.

PMID:40303365 | PMC:PMC12037579 | DOI:10.3389/fmed.2025.1542064

The comparative study of letibotulinum toxin A and onabotulinum toxin A in treatment of primary axillary hyperhidrosis

Arch Dermatol Res. 2025 Apr 1;317(1):661. doi: 10.1007/s00403-025-04069-2.

ABSTRACT

Primary axillary hyperhidrosis (PAH) is a challenging condition characterized by excessive underarm sweating. The U.S. Food and Drug Administration has approved onabotulinum toxin A (OnaBTX-A, Botox®, Allergan Inc, USA) as the only botulinum toxin treatment for severe axillary hyperhidrosis, and it has demonstrated positive results. Recently, the off-label use of letibotulinum toxin A (LetiBTX-A, Hugel®, Hugel Inc, Korea) has risen significantly for cosmetic purposes due to its effectiveness. For the treatment of primary axillary hyperhidrosis, the authors proposed that LetiBTX-A is at least as effective as OnaBTX-A. To evaluate the efficacy and safety of letibotulinum toxin A (LetiBTX-A) in comparison to onabotulinum toxin A (OnaBTX-A) for treating primary axillary hyperhidrosis (PAH). All participants with a diagnosis of moderate to severe primary axillary hyperhidrosis (Hyperhidrosis Disease Severity Scale (HDSS) score ≥ 2) received random injections of 50 U of LetiBTX-A in one armpit and 50 U of OnaBTX-A in the other site. HDSS score and hyperhidrosis area were measured by using the Minor’s iodine starch test. Participant satisfaction was evaluated at 1, 3, and 6 months following the injection. Onset of action and adverse events were also assessed. All 30 participants completed the study protocol, with the mean age was 34.44 ± 7.82 years and most of the participants were female. The mean age at onset was 20.47 ± 3.01 years and more than 50% of participants had a HDSS score of 3. There was no statistically significant difference observed in the reduction of HDSS scores, hyperhidrosis area, and participant satisfaction between the axillae treated with LetiBTX-A and those treated with OnaBTX-A at 1, 3 and 6 months after injections. The median onset of action of both LetiBTX-A and OnaBTX-A were 2 ± 1 day (p = 0.317). Procedure-related pain was comparable between 2 formulations (P = 0.876). No serious adverse event was observed. This study concluded that LetiBTX-A and OnaBTX-A demonstrate comparable efficacy and safety profiles in treating primary axillary hyperhidrosis (PAH).

PMID:40167830 | DOI:10.1007/s00403-025-04069-2