The term “hyperhidrosis” refers to perspiration that is excessive compared to what is necessary to control body temperature. This can cause social embarrassment, a decline in physical and emotional health, problems in personal relationships, and social stigmatization.
Topical antiperspirants like aluminium chloride, which are used as first-line nonsurgical therapy, are frequently unsuccessful at lowering sweat production, require frequent reapplication, and are uncomfortable as a result of irritating dermatitis.
Surgery techniques include removal of sweat glands, arthroscopic gland shaving, and endoscopic transthoracic sympathectomy (ETS). These procedures involve invasiveness, a high risk of significant consequences and recurrence, as well as the cost of a surgery, recovery period, and anaesthesia.
Therefore, the ideal treatment would be safer and less invasive than surgery, as well as longer lasting and more tolerable than topical agents, and it would result in high patient satisfaction rates.
Several randomised studies have shown that botulinum toxin type A is a safe, effective, and durable method of treating patients with primary hyperhidrosis.
According to research, when patients who have not responded to topical antiperspirants are given an injection of botulinum toxin, they experience a 75% reduction in sweating, an improvement in their emotional and physical well-being, and a reduction in their activity restrictions without experiencing any severe adverse reactions.
Primary hyperhidrosis is defined as: idiopathic; excessive sweating lasting six months or longer; having at least two of the following characteristics: interference with daily activities; symmetrical sweating on both sides of the body; frequency greater than once per week; and a family history of sweating.
Hyperhidrosis is not regarded as a psychiatric disease, even though emotional triggers exacerbate symptoms. Heat and spicy foods can also result in hyperhidrosis (gustatory hyperhidrosis).
Although the cause is unknown, it is thought to be caused by non-thermoregulatory sympathetic hyperstimulation of eccrine sweat glands.
To evaluate the severity of excessive sweat production and the level of patient impairment, several objective and subjective assessments have been devised.
This is one commonly used in aesthetic clinics.
The affected area’s skin is treated with an alcohol solution containing 3.5 percent iodine before being dusted with starch flour. Sweat coming into touch with the iodine-starch mixture causes the hue to shift to a dark violet. This denotes a positive sweat test and produces a map showing the location of active eccrine glands.
Some clinics will draw out a border on the hair line area which is believed to house the larger sweat glands
Hyperhidrosis Disease Severity Scale Score
Adapted from the Hyperhidrosis Disease Severity Scale study.
Positive tests will score 3 out of 4 on the scale.
Patients with severe blood-clotting disorders, secondary hyperhidrosis caused by an underlying condition, prior surgical debulking of the sweat glands, or those who have undergone previous debulking surgery are not eligible for botulinum toxin injections. Patients are needed to see the clinic again when their systemic or concurrent injection-site infections have cleared up. As with myasthenia gravis, Eaton-Lambert syndrome, or amyotrophic lateral sclerosis, refrain from treating people who already have a medical condition that may affect their ability to use their muscles. In addition, therapy is not available to female patients who are nursing or pregnant.
Botulinum Toxin Solution
Botulinum Toxin Type a Recommended Reconstitution
Diluent: 0.9% saline solution
Concentration: 25 U botulinum toxin to 1 ml 0.9% saline solution
Axillary dilution: 50 U botulinum toxin in 2 ml saline per axilla (3 ml for larger axillae); 40 injections per millilitre of injection solution
Palmar dilution: 100 U botulinum toxin in 3-4 ml saline per palm
Plantar dilution: 150-250 U botulinum toxin in 6-8 ml saline per sole
Inject botulinum toxin in the axillary area with a 26 – or 30-gauge needle on a TB syringe.
In most patients, 20 evenly distributed injection sites are placed sub-dermally in each axilla (20 injections per millimetre of injection solution), with the injection sites approximately 8 mm apart. The needle is inserted at a 45-degree angle, approximately 2 mm into the dermis, bevel side up. Once inserted, the syringe is slowly depressed to release approximately 0.1 ml (4units) of the solution sub-dermally, after which it is withdrawn.
A 26- or 30-gauge needle on a TB syringe is used for injection.
A 26- or 30-gauge needle on a TB syringe is used for injections.
The pain associated with BoNT-ONA injections for palmar and plantar hyperhidrosis can deter patients from undergoing the procedure. Due to the rich nerve endings in the palms and soles, pain can be significant with the numerous injections needed to achieve the desired effect. To reduce discomfort from the injection, several anaesthetic methods have been reported, including oral and intravenous sedation, topical lidocaine cream, nerve blocks, and cryoanalgesia (ice block). Radial and ulnar nerve blocks, when administered properly, are very effective in minimising pain and are commonly utilised prior to injection.
For patients who are more sensitive to pain or are wary of the pain associated with the injection, topical 2.5% lidocaine cream is applied 30 to 60 minutes prior to the procedure. Some physicians use vibration in conjunction with ice packs to reduce pain sensation. It is believed that the stimulation of vibration receptors inhibits the interneurons that transmit the pain signal. Vibration can be administered with a handheld massager or other similar device.
Define the injection field as a grid on the palm and sole. Once the field of injection is defined, a total of 100 U per palm of BoNT is injected with a 26- or 30- gauge needle and a TB syringe. The BoNT is diluted in 3 to 4 ml of normal saline and then sub-dermally injected into each 1- cm square area of the palm and three sites in each digit. After the procedure, ice packs are applied for 15 minutes to confirm no immediate reaction to the toxin.
Patients are monitored in the clinic for signs and symptoms of adverse events (AE) and encouraged to report any AE that occur following treatments and between follow-up visits. Patients are routinely advised to attend for a review in 2-4 weeks to check the treatment outcome. Patients are advised to self-refer for repeat treatment once their symptoms begin to return.
Patients who have undergone BTX-A injections claim a significant decrease in excess sweat production and improvement in quality of life.
The primary disadvantage to treating hyperhidrosis with botulinum toxin is its temporary improvement. Although there may be an attenuation effect, anhidrosis typically lasts six to nine months, and thus repeated injections are required. It is noted that patients who have had more than four treatments tend to return more frequently for subsequent injections. We speculate that this occurs because patients are less tolerant of symptoms once they become accustomed to the anhidrosis. However, research suggests that some patients may develop antibodies to the toxin, leading to reduced treatment efficacy.