The Use of Microneedles With Topical Botulinum Toxin for Treatment of Palmar Hyperhidrosis

Split-hand Microneedle group: After the subject has been consented, the Treatment Visit will commence. Subjects will be randomized into one of two groups. Binary randomization for microneedle pretreatment of the right vs. the left hand (Dominant hand has higher strength which may skew side effect reporting of weakness).

The evaluation of sweat production will be done using the subjective patient reported Hyperhidrosis Disease Severity Scale (HDSS) and objective gravimetric measurement. Hyperhidrosis Disease Severity Scale (HDSS) is a scale from 1 to 4. Values of 1 or 2 represent Mild/moderate disease, and 3 or 4 represent severe disease. Successful treatment is indicated by improvement from 3 or 4 to 1 or 2. One point improvement in HDSS score is associated with 50% reduction in sweat production and a two-point improvement with an 80% reduction, according to the Canadian Hyperhidrosis Advisory Committee.

Gravimetric measurement includes collecting sweat secretion on standardized filter. Prior to any measurements, the subject will be asked to sit in a climate-controlled room for 15 min to allow for acclimatization. Filter paper is first weighed on a high-precision laboratory scale. The filter papers are then placed in the subject's palms for 5 minutes, and weighed again. This technique has already been used in other studies of hyperhidrosis [5]. The difference in the weight (g) will allow calculation of sweat secretion in grams per 5 minutes.

The subject's palm will be cleansed with gauze. Then the microneedle pretreatment versus sham microneedle pretreatment will be performed. This will consist of rolling the microneedles or sham microneedles into the skin for several seconds on the sides of the palm that have respectively been randomized to the microneedle or control treatment. Sham microneedles will consist of a flat roller without the presence of the microneedles. The microneedles are solid and are long enough to penetrate the stratum corneum and enter the epidermis. Microneedles that are less than 700 micrometers in length have been shown to induce minimal pain, and our ongoing work with microneedles that were 650 micrometers in length was rated a 1 out of 10 on a visual analog pain scale. For this study, subjects will rate pain on a visual analog scale after the microneedle pretreatment as well.

Next a Transepidermal Water Loss Meter (Tewameter) will be used to measure the water evaporation gradient on the skin. Measurements will be performed with non-invasive devices that have been widely used for the study of skin barrier function. Each device has a flat-top electrode (approximate diameter of 1cm) that will come in contact with the skin surface during measurements. This device does not deliver any energy into the skin. The subjects will not experience discomfort during and after the measurements. The electrode tip will be cleaned with alcohol wipes between subjects.