Hyperhidrosis (HH), is a pathological condition of excessive sweating beyond the physiological needs for thermoregulation, which may severely disrupt a person’s quality of life and make their social interaction difficult, HH could be primary or secondary (1, 2). Primary focal hyperhidrosis (PFH)is defined as excessive, bilateral, and relatively symmetric sweating occurring in at least one of these sites: the axillae, palms, soles, or craniofacial region. PFH frequently results in occupational, psychological, and physical impairment, and can result in social stigmatization.
PFH results from the overactive sudomotor system which controls sweat output with no apparent cause (2). It is important to differentiate this condition from secondary hyperhidrosis, which could be due to many pathological conditions including endocrine disorders, infection, genetics, malignancy, neurologic, and miscellaneous causes (1, 2, 3). PFH accounts for 93% of all HH cases and can occur in otherwise healthy individuals without other medical problems (4).
Most often, secondary HH manifests as generalized exaggerated sweating, whereas PFH)- typically presents in a focal, bilateral, and symmetric distribution, commonly affecting the axillae (73%), hands (45.9%), feet (41.1%), and craniofacial regions (22.8%) (2, 3, 4).
From 1.6 to 4 million apocrine and eccrine sweat glands are distributed over the body, with a variable density of glands: 64 glands per cm2 located on the back, 181 glands per cm2 on the forehead, and 700 glands per cm2 on the palms (4, 5, 6). Thermoregulatory control is regulated through cerebral cortical centers, the anterior hypothalamus, and the sympathetic nervous system (6).
The pathophysiology of PFH is yet not fully understood. Sympathetic hyperactivity of otherwise healthy eccrine sweat glands has been described, which may be triggered by stimuli such as emotions or heat exposure (7).
PFH can occur at any age, but the usual onset occurs between 14 and 25 years of age, depending on the area affected (8). Palmar or plantar PFH usually appears at a prepubertal age, whereas axillary disease emerges more commonly during adolescence (6, 8, 9, 10). The incidence of PFH in individuals aged 18–39 years has been reported as 8.8%, in contrast to 2.1% in adults aged > 65 years and children. The uncommon occurrence of the condition in the elderly suggests its spontaneous regression (10). Both sexes are equally affected, with women seeking treatment
more frequently than men.
Epidemiological studies in the United States indicated that the prevalence of hyperhidrosis ranged from 0.6–9% in the particular populations studied; indicating this disease is not a rare event (8). It is interesting to note that the prevalence outside the United States is significantly higher and varies extensively, The observed prevalence of PFH is 13.9% in Japan, 14.5% in China, 16.3% in Germany, 16.7% in Canada, and 20.3% in Sweden (9, 10, 11, 12).
Also reported in 2002, patients with PFH had a 65% genetic prevalence of autosomal dominance with variable penetrance and no evidence of sex-linked transmission. This means that a child of a parent with PFH has a 25% chance of developing hyperhidrosis due to the likelihood of phenotypic expression of 0.28. It is also important to note that there is a potential genetic linkage to chromosome 14 (13).
The exact cause of PFH is unknown. The most reasonable etiology is a hyperexcitability or neurogenic overactivity of the normal eccrine glands, which is likely associated with a complex dysfunction of the parasympathetic and sympathetic elements of the autonomic nervous system (14). Additionally, the condition may result from a central control anomaly of emotional sweating, since the hands, feet, and axillae are affected in both PFH and emotional sweating
Early diagnosis and proper treatment of PFH are essential for minimizing its emotional, psychosocial, and physical effects (8, 15, 16). Exclusion of Secondary HH is mandatory before making a diagnosis of PFH. A complete medical history and physical examination should be performed, which frequently presents all information necessary to differentiate secondary HH from PFH (9). Laboratory tests are not recommended in typical PFH but should be implemented in atypical PFH and generalized HH cases (5, 14).
PFH has distinguishable characteristics, allowing its diagnosis to be made solely on the medical history and physical examination (1, 5). These characteristics include healthy young patients with a possible family history; focal, symmetric, and bilateral involvement of the hands, feet, and/or axillae; a possible history of aggravating stimuli (emotional, physical, and/or thermal); and cessation during sleep.
The Multi-Specialty Working Group on Hyperhidrosis proposed the Hornberg diagnostic criteria for PFH (Table 1) (1, 2, 17): at least 6 months of visible, detectable, focal, exaggerated sweating without any apparent explanation, and two or more of the following typical features: frequent occurrence of at least one incident/week; bilateral and somewhat symmetrical distribution; onset before 25 years of age; a positive family history; lack of focal sweating during sleep; and interference in daily activities.
Table 1
| PFH location | Frequency | Percent % | Cumulative Percent |
| | Both Axilla | 0 | 0 | 0 |
| | Both Axilla + Both Palm | 11 | 4.4 | 4.4 |
| | Both axilla + Both Palm + both Feet | 208 | 83.2 | 87.6 |
| | Both axilla + Both Palms + both Feet + Facial blushing | 31 | 12.4 | 100.0 |
| | Total | 250 | 100.0 | |
Medical history questions should focus on the age of disease onset, family history, HH pattern, the impact of HH on a patient’s daily life, other associated symptoms, and any medication intake to exclude secondary causes.
After establishing a diagnosis of PFH, severity must be determined (8). When sweating is visible during clinical examination, PFH severity can be classified based on the extent of sweating. Sweat stains on clothing can be useful for axillary involvement: sweat stain diameter < 5 cm is considered to be normal; stain diameter of 5–10 cm is considered mild HH; stain diameter of 10–20 cm is defined as moderate; and stain diameter > 20 cm and approaching the waistline is considered severe HH (5, 9, 12).
Regarding palmar HH, the following classifications have been devised: mild involvement sweaty hands without visible droplets; moderate involvement is when hand sweating reaches the fingertips; severe involvement sweat drips off the hand and extends to all fingertips (17).
Various quantitative and qualitative methods are available to establish a diagnosis of HH, its severity, and its effect on a patient’s quality of life (QoL) (13). Various quantitative sweat-production measurement tools are available for clinical purposes, with the gravimetry test and starch-iodine (Minor’s) test being the most commonly used (5).
In clinical practice, PFH is commonly determined in qualitative terms. Any amount that substantially interferes with an individual’s QoL and affects his/her daily life is determined to be abnormal sweating (13). That means the individual’s subjective perception of the impact of individual sweating on daily activities is the focus in diagnosing PFH. As a result, it is imperative to qualitatively measure the effects of PFH on a patient’s QoL, and any resultant daily life interference (12, 13, 14).
These data can be collected through history taking, specifically-designed questionnaires, or self-rated patient evaluations. Impact on QoL has evolved to be the most valuable and essential evaluation modality for PFH (9, 11, 12).
Various QoL evaluation questionnaires are available for PFH patients (15, 13). They can be HH disease-specific [such as the Hyperhidrosis Disease Severity Scale (HDSS) or the Hyperhidrosis Impact Questionnaire (HHIQ)], dermatology-related (such as the Dermatology Life Quality Index (DLQI) or Skindex), or general [such as the Short Form questionnaire-36 items (SF-36)] health-related assessments of QoL.
HDSS, DLQI, and Hyperhidrosis Quality of Life Questionnaire (HQLQ) are the most commonly used questionnaires in the literature for QoL evaluation in HH patients. It is common to find two or more questionnaires (such as DLQI and HDSS) being used concurrently. These tests have shown substantial QoL decline in various aspects of daily living in PFH patients (10, 13).
The Hyperhidrosis Disease Severity Scale (HDSS) (Table 2), is disease-specific, simple, and the most commonly used method for measuring QoL in HH patients was used preoperatively and the surgery decision was made for the cases with an HDSS scale of 3 &4 that the sweating is barely tolerable and intolerable and affecting daily activities respectively (11, 12, 13).
Table 2
A: comparison between the preoperative HDSS scores and postoperative scores.
| Preoperative HDSS scores | Post op HDSS score distribution | Total |
| 0 | 1 | 2 | 3 | 4 |
| 3 | 217 (86.8%) | 13 | 17 | 3 | 0 | 0 | |
| 4 | 33 (13.2%) | 132 | 65 | 19 | 1 | 0 |
| Total | 145 | 82 | 22 | 1 | 0 | 250 |
Table 2
B: Statistically significant improvement of the HDSS score by Pearson correlations
| | Pre-Operative HDSS | Post operative HDSS |
| Pre-Operative HDSS score | Pearson Correlation | 1 | − .105 |
| Sig. (2-tailed) | | .097 |
| N | 250 | 250 |
| Post operative HDSS score | Pearson Correlation | − .105 | 1 |
| Sig. (2-tailed) | .097 | |
| N | 250 | 250 |
Non-surgical treatment for PFH is widely described in the literature, this type of treatment is generally agreed to use for an HDSS score of one or two (1). The transient nature of these non-surgical treatment options may have non-satisfactory results due to the need for persistent adherence to therapy, especially in severe and intolerable cases of PFH (4, 6, 9, 12).
Whenever the HDSS is 3 or 4, surgical treatment is widely advised ( 1). The bulk of the randomized trials and nonrandomized comparisons identified the “ideal candidates” for Endoscopic Thoracic Sympathectomy (ETS) as those who have onset of hyperhidrosis at an early age (usually before 16 years of age), are young at the time of surgery (usually less than 25 years old), have an appropriate body mass index (≤ 28), report no sweating during sleep, are relatively healthy (no other significant comorbidities), and do not have bradycardia (resting heart rate ≥ 55 beats per minute) (1).
Different types of procedures are described in the literature such as sympathicolysis, sympathectomy, clipping of the chain, and interruption by ultrasonic scalpel; however, no procedure proved to be superior to others in terms of efficacy or a lower rate of complications (1, 3, 4, 6).
In the case of sympathectomy, both the sympathetic ganglia and chain are destroyed and partially removed. However, in the case of sympathicotomy, the sympathetic chain is only transected (1, 18).
Over the years, further refinements were made to optimize the endoscopic approach. The use of thoracoscopy equipment already enabled the use of small incisions, but the recent development of single-port thoracoscopy over more conventional bi- or tri-portal approaches decreased the degree of invasiveness even further (1, 4, 18).
Currently, endoscopic surgery is considered an effective treatment for moderate to severe palmar hyperhidrosis (1, 14, 15, 17, 18). Success rates of over 90% for curing or improving symptoms of severe palmar hyperhidrosis have been described.
Besides the differences in the nomenclature for techniques of targeting the sympathetic chain, the level of interruption is described with various definitions. Some studies describe the vertebral level of nerve interruption, while others refer to rib levels. As a consequence, literature comparisons of postoperative treatment success rates and complication rates are difficult to make.
For that reason, the Society of Thoracic Surgeons suggested in J. Clin. Med. 2022, 11, 786 3 of 10 their expert consensus to adopt an international nomenclature that refers to rib levels (R) as anatomic landmarks, instead of the vertebral level at which the nerve is interrupted (1).
As for patients with isolated palmar hyperhidrosis, interruption of the sympathetic nerve at the level of R3 is recommended (1). Other studies suggest interruptions at both levels R3 and R4 to achieve completely dry hands. Nevertheless, the risk of developing compensatory hyperhidrosis (CH), a common side effect associated with ETS, is higher in these patients. Besides these side effects, major complications, such as intraoperative bleeding, pneumothorax, and infections, may occur. To minimize perioperative risks, adequate screening and selection of patients are essential.
When complications occur, they should be adequately managed by experienced teams, and surgery should be carried out by surgeons trained in minimally invasive techniques (1).
The aim (objectives) of our study is to determine the efficacy and safety of ETS and long-term outcomes including quality of life and patient satisfaction.