Stem cell spreading dynamics intrinsically differentiate acral melanomas from nevi.

Early differential diagnosis between malignant and benign tumors and their underlying intrinsic differences are the most critical issues for life-threatening cancers. To study whether human acral melanomas, deadly cancers that occur on non-hair-bearing skin, have distinct origins that underlie their invasive capability, we develop fate-tracing technologies of melanocyte stem cells in sweat glands (glandular McSCs) and in melanoma models in mice and compare the cellular dynamics with human melanoma. Herein, we report that glandular McSCs self-renew to expand their migratory progeny in response to genotoxic stress and trauma to generate invasive melanomas in mice that mimic human acral melanomas. The analysis of melanocytic lesions in human volar skin reveals that genetically unstable McSCs expand in sweat glands and in the surrounding epidermis in melanomas but not in nevi. The detection of such cell spreading dynamics provides an innovative method for an early differential diagnosis of acral melanomas from nevi.

Management of Primary Focal Hyperhidrosis: An Algorithmic Approach.

Hyperhidrosis (HH) is defined as perspiration beyond the level required to maintain temperature regulation. HH affects nearly 4.8% of the population in the United States. It can have a great impact on patient’s quality of life by disturbing daily activity, performance, confidence, social interactions, and mental health. In the majority of patients with HH (93%), the etiology of excess sweating is idiopathic, which classifies it as primary focal HH. Mild HH may be controlled with topical antiperspirants and lifestyle modifications. Based on the location of involvement, iontophoresis and botulinum toxin may be considered if the patient does not respond to topical therapies. Despite minimizing sweating, chronic use of systemic anticholinergics, in particular oxybutynin, may result in detrimental adverse effects such as dementia. Local surgery, radiofrequency, microwave, and lasers are other potential modalities for HH. Sympathectomy can be a last resort for the treatment of focal HH of the palmar, plantar, axillary, and craniofacial areas after failure of less invasive therapeutic options. In this review, we conducted a comprehensive search in the PubMed electronic database to summarize an algorithmic approach for the treatment of HH. This can help broaden options for managing this difficult disease. J Drugs Dermatol. 20(5): doi:10.36849/JDD.5774.

The etiology, diagnosis, and management of hyperhidrosis: A comprehensive review: Therapeutic options.

Hyperhidrosis (HH) is a chronic disorder of excess sweat production that may have a significant adverse effect on quality of life. A variety of treatment modalities currently exist to manage HH. Initial treatment includes lifestyle and behavioral recommendations. Antiperspirants are regarded as the first-line therapy for primary focal HH and can provide significant benefit. Iontophoresis is the primary remedy for palmar and plantar HH. Botulinum toxin injections are administered at the dermal-subcutaneous junction and serve as a safe and effective treatment option for focal HH. Oral systemic agents are reserved for treatment-resistant cases or for generalized HH. Energy-delivering devices such as lasers, ultrasound technology, microwave thermolysis, and fractional microneedle radiofrequency may also be utilized to reduce focal sweating. Surgery may be considered when more conservative treatments have failed. Local surgical techniques, particularly for axillary HH, include excision, curettage, liposuction, or a combination of these techniques. Sympathectomy is the treatment of last resort when conservative treatments are unsuccessful or intolerable, and after accepting secondary compensatory HH as a potential complication. A review of treatment modalities for HH and a sequenced approach are presented.

Interventional management of hyperhidrosis in secondary care: a systematic review.

BACKGROUND: Hyperhidrosis is uncontrollable excessive sweating, which occurs at rest, regardless of temperature. The symptoms of hyperhidrosis can significantly affect quality of life. OBJECTIVES: To undertake a systematic review of the clinical effectiveness and safety of treatments available in secondary care for the management of primary hyperhidrosis. METHODS: Fifteen databases (including trial registers) were searched to July 2016 to identify studies of secondary-care treatments for primary hyperhidrosis. For each intervention randomized controlled trials (RCTs) were included where available; where RCT evidence was lacking, nonrandomized trials or large prospective case series were included. Outcomes of interest included disease severity, sweat rate, quality of life, patient satisfaction and adverse events. Trial quality was assessed using a modified version of the Cochrane Risk of Bias tool. Results were pooled in pairwise meta-analyses where appropriate, otherwise a narrative synthesis was presented. RESULTS: Fifty studies were included in the review: 32 RCTs, 17 nonrandomized trials and one case series. The studies varied in terms of population, intervention and methods of outcome assessment. Most studies were small, at high risk of bias and poorly reported. The interventions assessed were iontophoresis, botulinum toxin (BTX) injections, anticholinergic medications, curettage and newer energy-based technologies that damage the sweat gland. CONCLUSIONS: The evidence for the effectiveness and safety of treatments for primary hyperhidrosis is limited overall, and few firm conclusions can be drawn. However, there is moderate-quality evidence to support the use of BTX for axillary hyperhidrosis. A trial comparing BTX with iontophoresis for palmar hyperhidrosis is warranted.

Microwave Treatment for Axillary Hyperhidrosis and Bromhidrosis. / Tratamiento con microondas en la hiperhidrosis y bromhidrosis axilar.

Axillary hyperhidrosis (AH) and bromhidrosis are common causes of consultation in dermatology. Currently, the most widely prescribed treatment for AH is botulinum toxin, a very effective but temporary option; it is totally ineffective in bromhidrosis. Sympathectomy is an increasingly infrequent choice of treatment due to the high incidence of compensatory hyperhidrosis. We describe the treatment of AH and bromhidrosis with a novel microwave device that can fibrose eccrine and apocrine glands, achieving possibly permanent results. The procedure should preferably be performed under tumescent anesthesia. Side effects, principally local inflammation, are transient. Clinical effectiveness and safety, supported by recently published studies, position this technique as a first-choice option both for hyperhidrosis and for bromhidrosis.

Treatment of hyperhidrosis with microwave technology.

Hyperhidrosis is the production of sweat above and beyond normal physiological needs, regardless of the ambient temperature, and it affects > 4% of the population. In addition, a poll showed up to 21% of the population is bothered on a daily basis by their amount of underarm sweating. Despite the large number of patients who suffer from hyperhidrosis, there are relatively few effective nonsurgical treatment options. A new, nonsurgical, lasting treatment for axillary hyperhidrosis has now been developed using microwave technology to eliminate sweat glands.

Modelling millimetre wave propagation and absorption in a high resolution skin model: the effect of sweat glands.

The aim of this work was to investigate the potential effect of sweat gland ducts (SGD) on specific absorption rate (SAR) and temperature distributions during mm-wave irradiation. High resolution electromagnetic and bio-heat transfer models of human skin with SGD were developed using a commercially available simulation software package (SEMCAD X™). The skin model consisted of a 30 µm stratum corneum, 350 µm epidermis and papillary dermis (EPD) and 1000 µm dermis. Five SGD of 60 µm radius and 300 µm height were embedded linearly with 370 µm separation. A WR-10 waveguide positioned 20 µm from the skin surface and delivering 94 GHz electromagnetic radiation was included in the model. Saline conductivity was assigned inside SGD. SAR and temperatures were computed with and without SGD. Despite their small scale, SAR was significantly higher within SGD than in the EPD without SGD. Without SGD, SAR and temperature maxima were in the dermis near EPD. With SGD, SAR maximum was inside SGD while temperature maximum moved to the EPD/stratum-corneum junction. Since the EPD participates actively in perception, the effect of SGD should be taken into account in nociceptive studies involving mm-waves. This research represents a significant step towards higher spatial resolution numerical modelling of the skin and shows that microstructures can play a significant role in mm-wave absorption and induced temperature distributions.

Does human skin truly behave as an array of helical antennae in the millimeter and terahertz wave ranges?

The sweat ducts of the human perspiration system are helically shaped tubes, filled with a conductive aqueous solution. Recent studies have claimed that these ducts act as an array of low-Q helical antennae and are dominant in shaping the spectral response in the subterahertz region. Using local homogenization theory for the skin embedded with sweat ducts, we found that multiple interference effects from the skin layers play the major role in determining the skin electromagnetic characteristics in the millimeter and terahertz regions without the need for the assumption of the sweat ducts acting as low-Q helical antennae.

Distortion of millimeter-wave absorption in biological media due to presence of thermocouples and other objects.

Specific absorption rate (SAR) distributions in the vicinity of a thermocouple or air bubble in water and in the presence of hair or sweat duct in skin were calculated using analytical and two-dimensional impedance methods. The objects were exposed to uniform 42.25 GHz plane electromagnetic fields. Insertion of a 0.1-mm thermocouple or similarly sized air bubble into water produced a strong localized disturbance of the otherwise uniform SAR distribution. However, the average of SAR values immediately surrounding the thermocouple was close to the undisturbed uniform average SAR. This allows measuring the average SAR during exposure of both unbounded and bounded media using calibrated small thermocouples (up to 0.1 mm). The SAR distribution in the vicinity of a hair was qualitatively similar to that produced by an air bubble. The maximal value of SAR was more than three times higher than the overall average SAR value in the skin. Sweat ducts produced a smaller disturbance of the millimeter-wave (mm-wave) field.

Sweat gland function as a measure of radiation change.

BACKGROUND: Radiotherapy may result in dryness of the skin even when no other change can be detected. We describe a system for recording the electrical conductance of skin as a measure of sweat gland function. PATIENTS AND METHODS: In 22 normal volunteers close agreement was obtained between measurements obtained from comparable sites on both sides of the chest. Measurements were subsequently made in 38 patients treated by radiotherapy to one side of the chest for tumours of the breast or lung using one of five different fractionation schedules. Simultaneous readings were obtained from both sides of the chest with the non irradiated side acting as a control. RESULTS: A dose response relationship was demonstrated: five patients who received the equivalent total dose of 15 Gy in 2-Gy fractions showed no change in conductance. Sixteen out of 23 who received an equivalent total dose of 42-46 Gy in 2-Gy fractions had a greater than 22% reduction in mean skin conductance compared with that of the control areas despite the skin appearing normal in the large majority. Marked changes in skin conductance were seen after higher total doses. In a prospective study 18 women receiving breast irradiation underwent weekly readings during treatment. A mean reduction of 40% in skin conductance was noted by the end of the second week of treatment prior to any clinical evidence of radiation change. Skin conductance returned to normal in 44% of patients by 6 months. In the remainder, those patients who showed the greatest reduction in skin conductance during treatment demonstrated the least recovery. CONCLUSIONS: Changes in sweat gland function can be detected and quantified in skin which may otherwise appear normal. Differences may so be demonstrated between areas treated using different fractionation schedules and the method may be applied to the detection during radiotherapy of unusually sensitive patient.

Electron beam therapy. Its effect on eccrine gland function in mycosis fungoides patients.

An observed clinical side effect of total skin surface electron beam therapy is the patient's inability to perspire. An evaluation of eccrine sweat gland function was performed, utilizing acetylcholine chloride and a silicone impression material. The patient's inability to sweat after therapy, and recovery within a three- to six-month period after therapy was demonstrated. This phenomenon should be appreciated by both the physician and the patient prior to electron beam therapy in order to avoid the potential complications of this condition.