Axillary hyperhidrosis: An update

Topical

Aluminum salts (12.5–30%) constitute the first line of treatment. There is occlusion of the distal ducts, and prolonged blockage of the glands leads to acinar degeneration and reduced sweat. Aluminum ions precipitate with mucopolysaccharides and damage the epithelial cells along the ductal lumina and block sweat secretion. The formulation should be applied on dry skin at night. Side effects include miliaria, irritation, and burning. Low-potency corticosteroid creams may reduce the irritation.^[12]

A novel topical foam has been developed (Versafoam), which contains 20% aluminum sesquichlorohydrate. It reduces the amount of sweating by 50%–60%. Side effects have not been reported.^[13,14]

Topical glycopyrrolate 2% used twice daily, is a good agent. Conflicting results have been noted in different studies. Overall, the evidence seems to be lacking. Besides, anticholinergic gels of different concentrations, oxybutynin and umeclidinium, are being investigated. Topical sofpironium bromide has also been tried.^[15-18]

Botulinum toxin Type A has demonstrated significant reduction in the production of sweat. No serious adverse events were noted. It should be remembered that misuse may lead to ptosis and facial asymmetry. Newer topical formulations for botulinum toxin are being investigated.

Systemic

Anticholinergic drugs such as glycopyrrolate, oxybutynin, and bornaprine are useful. However, the side effects such as dry mouth, blurring of vision, dryness of eyes, and urinary retention limit the use of these agents. Other medications including beta-blockers and clonidine (0.5 mg BD) are also used.^[19-22]

Injectables

Botulinum toxin is an inhibitor of acetylcholine release. Two types of botulinum toxin were extensively tested for axillary hyperhidrosis: Onabotulinumtoxin A and abobotulinumtoxin A. Prior to initiating treatment with botulinum toxin, patient history should be taken in details. The primary underlying disease should be treated, patient should be well educated about the potential adverse effects, contraindications, and alternative treatments. The need for reinjection after 6–9 months should be explained to the patient. Pregnancy and lactation periods are highly contraindicated. Patients with pre-existing comorbidities such as myasthenia gravis, Eaton-Lambert syndrome, or amyotrophic lateral sclerosis are not fit for the therapy. Use of 50–100 U is recommended in each axilla. Anesthetic creams and application of ice packs and vibration reduce pain. The procedure requires multiple injections, with 1–2 cm distance between them. The toxin vial is diluted in 2 mL of 0.9% saline solution and 2 U injected per point. The median duration of the effect of the toxin is 7.6 months. After dilution, it must be stored in a refrigerator at 2–8°C and must be used within 4 h of reconstitution. A 30 gauge or insulin syringe is used at an angle of 45 approximately 2 mm into the dermis. The minimum dose for each injection is from 2.0 to 2.5 U depending on the colorimetric response generated by minor starch test. As the diffusion capacity of botulinum toxin injection is 1.0–1.5 cm in diameter, the injected points should be this distance apart. The literature reveals that the botulinum toxin A has a reported effectiveness of higher than 90% for hyperhidrosis and has greater improvements within the first 22 weeks of treatment, and the effect lasts for 4–9 months only.^[23-26]

Iontophoresis

A small electric current is made to pass through the electrodes for 20–30 min. However, the treatment is not very effective. The combined use of anticholinergic agents, such as poldine methylsulfate and glycopyrronium bromide, can increase the effectiveness of iontophoresis.^[27-31]

Cryotherapy

It is used on the sites of nerve block injections combined with or without iontophoresis (2% lignocaine for 15 min). Major adverse effect is the formation of blisters.^[32]

Newer therapies

Microwave thermolysis has been successfully used in treating hyperhidrosis.^[33-35] MiraDry® is a US FDA-approved device for this. Here, heat waves destroy the eccrine and apocrine glands. Before the start of the procedure, an injectable local anesthetic is given to decrease the pain. Two applications are performed at 3 months interval. Side effects include pain, ecchymosis, edema and erythema, and rarely brachial plexus damage. In some cases, sensitization is required that lasts for 5 weeks. Here, there is reduction in sweating that lasts for about 2 years after treatment. Besides, microneedling has also been tried.^[36]

Lasers

Nd:YAG 1064 nm and other lasers show significant reduction in hyperhidrosis when associated with surgical excision of the glands.^[37-42]

Microfocused ultrasound

The ultrasound energy is applied to 4.5 mm of the skin surface 2 times, over an interval of 30 days resulting in significant improvement.^[43,44]

Surgery

Aspiratory curettage provides long-lasting results in hyperhidrosis. This therapy is preferred as it does not need periodic repetition, less expensive and it has minimum risks. Endoscopic thoracic sympathectomy may be done in recalcitrant cases.^[45-57]