Treatment of Focal Hyperhidrosis With Needleless Injections of Botulinum Toxin Into Sites Other Than the Axilla, Palm, and Sole
Injections of botulinum toxin Type A (BTX-A) to treat HH have favorable effects on the affected regions of the body. However, few studies have reported injections of BTX-A using the needleless technique in the perianal area, scalp (scalp sweating), and trunk (compensatory sweating [CS]).1,2 Considering the difficulties and discomfort associated with conventional syringe techniques for administering a series of BTX-A injections because of the limitations of external topical anesthetics, cryoanalgesia, and nerve blocks, the needleless Dermojet (DMJ; AKRA Dermojet, Pau, France) and SheMax (SM; Shenb Co., Ltd., Seoul, Korea)3 are useful for obtaining favorable outcomes in the treatment of HH. Moreover, the surgical and medical approaches for HH management do not routinely achieve adequate efficacy.
Various needleless devices that are powered by an appropriate pressure system and that inject all types of liquid (anesthetics and medications) are available.4 The needleless DMJ and SM are among the devices used to reduce sweating in focal regions of the body. The DMJ has been used to treat palmar and plantar HH,4,5 whereas the SM, transcutaneous pneumatic injection system, has a 200-μm nozzle diameter, generates a small entry point, and transports therapeutic solutions to targeted layers of the skin in a minimally invasive manner, depending on the pneumatic pressure and the viscosity of the solution, for cosmetic purposes (face lifts, wrinkles, and atrophic scars).3
HH in the perianal region is a rare form of focal HH for which prevalence and etiology data are not available. Excessive sweating in the perianal area may cause severe stress related to the discomfort associated with wet skin, feeling of moisture, development of eczema, and foul odor. Two patients indicated that the minimal pain of the DMJ injection of BTX-A was acceptable, they were satisfied with their treatment, and improved social performance was noted because of reduced sweating that lasted up to 4 to 6 months (Figure 1).
Scalp sweating is a craniofacial form of HH that affects the entire scalp and features excessive sweat running down the neck and face. This cranial HH produces intense undesirable consequences and has a debilitating influence on quality of life, especially in warm weather. Topical glycopyrrolate, oral medication, and intradermal BTX-A are considered first-line treatments because of their efficacy and safety. T2 sympathectomy should be considered the last option for patients at high risk of CS and for those whose conditions are intractable to first-line therapy. As no studies have examined the treatment of patients with focal HH of the scalp using intradermal BTX-A, in our experience, this treatment has an important role in the management of HH during the summer. Sweating was eliminated in 20 patients after intradermal injections of BTX-A, which is an effective, safe, and long-term treatment for focal HH. However, the administration of a series of injections through the skin without regional block anesthesia or a conventional syringe injection, despite use of a 29-gauge needle, is painful and bothersome. Thus, the needleless injection system of SM is an excellent alternative tool for conveniently delivering serial injections (Figure 2).
CS, the most recognized and common side effect of endoscopic thoracic sympathectomy, is disruptive because afflicted individuals may have to change sweat-soaked clothing 2 or 3 times a day in the summer. Large untreated areas of the body, most commonly the chest and back of the trunk, may sweat excessively. CS is difficult to treat and lacks an efficient, available treatment modality.