Also known as sweaty underarms
What is axillary hyperhidrosis?
Axillary hyperhidrosis, or excessive underarm sweating, is a common condition affecting up to 3% of the population. Axillary hyperhidrosis usually starts in childhood or adolescence but some people first experience it as adults. The impact of this condition is often underestimated – it can affect work and social situations and may cause significant psychological distress. Fortunately, effective treatments are readily available.
What causes axillary hyperhidrosis?
Many factors can contribute to axillary hyperhidrosis including genetic influences as well as physical and emotional stress. A family history is present in up to 30% of cases.
What does axillary hyperhidrosis look like?
It may be mild with occasional sweaty patches or severe with constant sweating throughout the waking hours of the day. Severe cases are very distressing and can significantly affect a person’s quality of life.
Axillary hyperhidrosis is often associated with sweating elsewhere on the body including the hands (palmar hyperhidrosis), feet (plantar hyperhidrosis) and face (craniofacial hyperhidrosis).
How is axillary hyperhidrosis diagnosed?
The diagnosis is usually made based on a history of excessive sweating. No investigations are needed.
Further investigations are considered when larger areas of the body are affected or if hyperhidrosis occurs during sleep.
How is axillary hyperhidrosis treated?
The choice of treatment will depend on how severe the sweating is, affordability of treatment and whether a permanent solution is desired.
- Topical treatments
Mild cases can respond to topical treatments such as aluminium chloride hexahydrate (Driclor).
Driclor should always be applied to skin that is as dry as possible in order to maximise the benefit and minimise potential side effects. Ideally, it should be applied just after a shower prior to bedtime. Dry the area off with a hairdryer on the cool setting then apply Driclor. Wash off the area first thing in the morning with plain water (no soap). If irritation develops, applying a corticosteroid cream intermittently can be useful (this needs to be used under the guidance of a health professional).
Anticholinergic creams such as glycopyrolate (0.5-3%) can also be effective. A compound pharmacist can make up these creams. Side effects are uncommon.
- Botulinum toxin type A (botox) injections
Botox has been approved for treating severe cases in people who have had no improvement after two months using Driclor. It is effective in up to 95% of cases.
Treatment takes less than five minutes. Botox is injected into the areas of excessive sweating. It typically controls sweating for 4 to 7 months.
Side effects are exceedingly rare but include temporary pinpoint bleeding, bruising and redness in the injected sites. Individuals can resume normal activities after the procedure but exercise should be limited for 24 hours after treatment.
Under Medicare and PBS guidelines, up to 3 treatments are subsidised per year with a minimum of 4 months between treatments, provided patients meet eligibility criteria.
- Oral medication
Anticholinergic tablets (such as oxybutynin and propantheline bromide) can be useful for axillary hyperhidrosis. However, side effects such as blurred vision, constipation, dry mouth and excessive drowsiness are common.
Other medications reported to be useful include glycopyrrolate orally (not available in Australia), propranolol, clonazepam and gabapentin.
Medication can be a viable short-term option for treating sweaty underarms for several days to weeks and give people a “break” from their sweating.
This is a relatively new treatment option which uses microwave energy to heat and destroy the sweat glands. It is a non-surgical treatment performed under local anaesthetic in the doctor’s surgery for moderate to severe underarm sweating. Two treatments, spaced 3 months apart, may permanently reduce sweating by over 80%.
Some people will also have sweating in other areas of the body such as the hands, feet and face but miraDry cannot be used to treat these areas.
- Endoscopic thoracic surgery
Endoscopic thoracic sympathectomy (ETS) is a surgical treatment option for various forms of hyperhidrosis. It is conducted by a vascular or neurosurgeon under general anaesthesia. The main risk to be considered is the chance of compensatory or rebound hyperhidrosis, which may occur in 25-50% of cases. However, ETS is rarely considered as a treatment for axillary hyperhidrosis nowadays, due to other treatments such as Botox or miraDry having better results and safety profile.
What is the likely outcome of axillary hyperhidrosis?
Axillary hyperhidrosis tends to be a chronic condition, though the level of sweating may diminish in older adult life.
This information has been written by Dr Davin Lim