Pathophysiology of Hyperhidrosis.

Studies and case reports on excessive sweating frequently state that hyperhidrosis is a disease whose origin and mechanism are unknown. However, the term excessive is rarely based on systematic diagnostic measurements, instead being a description of the symptoms from patient histories, which suggests that hyperhidrosis is purely a problem involving the quantity of sweat, whereas it is a change in the control mechanism of sweating in which the need for and production of sweat are strongly disproportionate. This lack of proportion is perceived by those affected to be a limitation of activities of daily living and is thus pathologic.

Radiofrequency Thermotherapy for Treating Axillary Hyperhidrosis.

BACKGROUND: Thermotherapy has been established between conservative and surgical options as a minimally invasive method for the treatment of axillary hyperhidrosis. OBJECTIVE: The objective of this study was to present radiofrequency thermotherapy (RFTT) as a safe and effective new treatment method. MATERIALS AND METHODS: Thirty adult patients with pronounced axillary hyperhidrosis were treated with RFTT with noninsulated microneedles 3 times at intervals of 6 weeks. Subjective improvement was rated using the Hyperhidrosis Disease Severity Scale (HDSS) and Dermatology Life Quality Index (DLQI). Satisfaction and estimated reduction of sweating were monitored. Objective measurements were made using gravimetry. Adverse effects were recorded in follow-up. At the 6-month follow-up, improvement in sweating was seen in 27 patients. The HDSS dropped from 3.4 to 2.1, the DLQI improved significantly from 16 to 7. The gravimetric measurements of sweat were reduced from 221 to 33 mg/min. The average reduction of sweating was reported to be 72%. Adverse effects were generally mild and improved rapidly. CONCLUSION: Radiofrequency thermotherapy was shown to be an effective and minimally invasive treatment option for axillary hyperhidrosis. Patients described their sweating as normal. The method clearly has the potential to normalize axillary sweating.

Thoracic sympathectomy: a review of current indications.

BACKGROUND: Thoracic sympathetic ablation was introduced over a century ago. While some of the early indications have become obsolete, new ones have emerged. Sympathetic ablation is being still performed for some odd indications thus prompting the present study, which reviews the evidence base for current practice. METHODS: The literature was reviewed using the PubMed/Medline Database, and pertinent articles regarding the indications for thoracic sympathectomy were retrieved and evaluated. Old, historical articles were also reviewed as required. RESULTS AND CONCLUSIONS: Currently, thoracic sympathetic ablation is indicated mainly for primary hyperhidrosis, especially affecting the palm, and to a lesser degree, axilla and face, and for facial blushing. Despite modern pharmaceutical, endovascular and surgical treatments, sympathetic ablation has still a place in the treatment of very selected cases of angina, arrhythmias and cardiomyopathy. Thoracic sympathetic ablation is indicated in several painful conditions: the early stages of complex regional pain syndrome, erythromelalgia, and some pancreatic and other painful abdominal pathologies. Although ischaemia was historically the major indication for sympathetic ablation, its use has declined to a few selected cases of thromboangiitis obliterans (Buerger's disease), microemboli, primary Raynaud's phenomenon and Raynaud's phenomenon secondary to collagen diseases, paraneoplastic syndrome, frostbite and vibration syndrome. Thoracic sympathetic ablation for hypertension is obsolete, and direct endovascular renal sympathectomy still requires adequate clinical trials. There are rare publications of sympathetic ablation for primary phobias, but there is no scientific basis to support sympathetic surgery for any psychiatric indication.

Thoracoscopic sympathectomy at the T2 or T3 level facilitates bradykinin-induced protein extravasation in human forearm skin.

BACKGROUND: The endogenous peptide bradykinin (BK) is an inflammatory mediator that induces nociceptor activation and sensitization as well as protein extravasation and vasodilation. OBJECTIVE: To test the hypothesis if sympathectomy affects BK-induced inflammation in humans. METHODS: Dermal microdialysis was employed on the volar forearm in 10 patients (21-41 years) with regional hyperhidrosis before and three months after preganglionic endoscopic transthoracic sympathetic clipping (ETSC) at the T2 or T3 level and in 10 healthy volunteers (22-36 years). After 60 minutes perfusion with Ringer's solution microdialysis fibers were perfused with BK 10(-7) M and 10(-5) M for 30 minutes followed by 30 minutes Ringer's solution again. To assess protein extravasation dialysate protein content was measured photometrically and Laser-Doppler imaging was used to quantify axonreflex vasodilation. RESULTS: Baseline flux values after ETSC were higher as compared with controls and preoperative values (anova, Bonferroni post hoc test, P < 0.05), but neither BK 10(-7) M nor 10(-5) M led to significant vasodilation. Baseline dialysate protein did not significantly differ between groups. BK 10(-5) M induced protein extravasation while BK 10(-7) M was ineffective, and BK 10(-5) M induced protein extravasation was significantly enhanced after ETSC (P < 0.001). CONCLUSIONS: Forearm skin perfusion is increased after ETSC on the T2 or T3 level indicating decreased sympathetic activity while BK-induced protein extravasation was increased. These results show that preganglionic sympathectomy does not diminish bradykinin-induced protein extravasation as found for postganglionic sympathectomy in rats.

Sequelae of endoscopic sympathetic block.

Endoscopic sympathetic block as a treatment for primary hyperhidrosis is associated with certain sequelae. The reported occurrence of side effects still varies in the literature. As the majority of patients describe sequelae after sympathetic surgery, the frequency and importance of these persisting changes are still underestimated. Patient's informed consent should include and define side effects like gustatory sweating, olfactory sweating and bradycardia as likely, and compensatory sweating as obligatory.

Effects of gender and level of surgical sympathetic block on vasoconstrictor function.

Interruption of sympathetic outflow by surgical sympathetic block has been used to treat hyperhidrosis for decades. In this study the effect of gender and the level of sympathetic block (T2 vs. T3) on the rewarming kinetics following ice water immersion were assessed in a prospective study on 60 hyperhidrosis patients before, 2 days, and 3 months postoperatively. Rewarming kinetics following endoscopic sympathetic block (ESB) was massively enhanced 2 days post-operatively, but had returned to pre-operative conditions at the 3 month follow-up for ESB at level T3. ESB at level T2 provoked significantly faster rewarming as compared to T3 at the 2 day and 3 month follow-up. Independent of the level of ESB, there was a slower rewarming in women already pre-operatively. This gender difference was clearly reduced at the 2 day follow-up, but had increased again at the 3 month follow-up. There was no correlation between the rewarming kinetics of the fingertips and palmar sweating. We conclude that for the sympathetic vasoconstriction of the fingertips the sympathetic ganglion T2 is crucial. Gender differences have to be taken into account when assessing effect of ESB by cold induced vasoconstriction. It remains to be established whether the quantification of vasoconstriction has some predictive value for the long-term prognosis of sudomotor blockade.

Differential effects of surgical sympathetic block at the T2 and T4 level on vasoconstrictor function.

Endoscopic sympathetic block (ESB) is used as a treatment of excessive palmar sweating. In a prospective study we compared the effect of ESB at the level of the second (T2) and fourth thoracic ganglion (T4) on vasoconstriction and sweating of the hands. Sympathetic vasoconstriction was measured by computerassisted infrared thermography following ice water immersion of the hands in 22 hyperhidrosis patients before, two days and 3 months post op. In addition, palmar sweating before and 3 months post op was assessed by sudometry. After ESB the rewarming was accelerated in both T2 and T4 patients, but was significantly slower in the T4 group. Three months postoperatively rewarming had returned to the preoperative pattern in T4 patients but was still significantly faster in the T2 group. These effects were more pronounced in the fingertips than the hand dorsum. Sudomotor function was blocked in all T2 patients but had relapsed in 2 patients in the T4 group. Two T4 patients had not shown an effect on sudomotor function postoperatively. The normalization of rewarming kinetics may be explained by remaining fibers, denervation hypersensitivity or stimulation of catecholamine receptors, or neuronal reorganization. The effect of ESB T4 on sudomotor function has to be proven.