[Benson RA, Palin, R, Holt PJE et al. Diagnosis and management of hyperhidrosis. BMJ 2013; 347: f6800.]
Now, hyperhidrosis is the medical term for excess sweating. Sweating is a normal physiological phenomenon and plays a key part in the regulation of body temperature. Evaporation of body sweat cools the body and hence why we sweat when we exercise, for example. I’m sure, however, that we can all recognise scenarios where we sweat when we are not exercising. These can vary from difficult social situations or when we are anxious or stressed, for example.
There are 2 types of hyperhidrosis.
We classify hyperhidrosis into primary and secondary. Primary hyperhidrosis is where we cannot find an underlying cause and the person is otherwise healthy. Secondary hyperhidrosis is where an underlying condition (such as certain infections, endocrine or neurological conditions) or drugs is driving the hyperhidrosis.
How do you get hyperhidrosis?
I always explain to patients who get referred with hyperhidrosis that we have 2 sets of nerves in the body (the sympathetic and the parasympathetic) and one set balances the other. If, however, there is an imbalance between the 2 nervous systems (and the sympathetic system wins, so to speak) then hyperhidrosis can result.
The glands that sweat for us are called the eccrine glands and these are located in the palms, soles and armpits (axillae is the medical term). Normal sweating of the palms and soles occurs from birth. Apocrine glands also produce sweat and are situated in the armpits, but also the palms and soles, scalp and groin. These start to function at puberty and hence why the problem most commonly presents after the onset of puberty. These apocrine glands are regulated by the sympathetic nervous system. Axillary hyperhidrosis is the commonest type followed by hands, feet, scalp and then the groin.
So it’s just a bit more sweat than normal. So what?
Many sufferers experience a poor quality of life because of their hyperhidrosis. It can affect their social relationships, work and schooling and many feel embarrassed about shaking hands with people or about standing up and presenting or even report problems with handling innocuous objects such as pens.
Why do some people get it and not others?
This is not known. We know that things such as stress, anxiety, heat, exercise, smoking, alcohol and hot spices can trigger it.
How do I know if I have hyperhidrosis or not?
Excess sweating is quite hard to define but a level of sweating that has an unacceptable quality of life is a good guide. The patients that I see tend to report ‘rivers of sweat’ from their armpits with just sitting in ambient room temperature and one can often see pools of sweat in the palms without any preceding exercise or other triggering factors.
Doctors will check to make sure the sweating is not generalised and that there are no signs of an underlying condition driving it. Patients may be asked questions about their general health and blood tests may be requested, for example, to look at thyroid function or diabetes.
What treatments are there for hyperhidrosis?
Well, starting with the simple things, NICE have produced recommendations such as avoiding triggers such as crowded rooms, caffeine and spicy foods, avoiding tight clothing, wearing white or black clothing to minimize signs of sweating, using dress shields (which can be obtained via the Hyperhidrosis Support Group) and using a commercial antiperspirant rather than a deodorant.
Are there any other treatments than that?
Yes, there are topical treatments of which aluminium chloride preparations are the most widely used and hence they are first line. It is thought that the aluminium ions are taken up by the sweat duct cells, causing water to flow in to the cells by osmosis which makes the cells swell. These swollen cells then block off the sweat duct, thereby preventing the sweat from leaving the sweat duct on to the skin. Driclor® and Anhydrol Forte® are roll-on versions which are licensed and can be bought at the chemist or prescribed. Zeasorb® is an aluminium salt dusting powder that can be used for hyperhidrosis of the palms or soles. They can all cause skin irritation which might be improved with moisturisers, mild steroids or reducing the frequency of application. The effects of these agents are, however, only temporary.
If all of the above has been trialled for at least 6 weeks with no success, patients should be referred to a dermatologist.
So what other treatments are there in secondary care?
Iontophoresis – this is where the patient puts their palms or soles in a little tray filled with water and a current of 15-20mA electricity is run through this. Pads soaked in water and connected to the electric field can be used for the armpits. The treatment lasts about 30 minutes and side effects include a burning sensation or some redness. The science behind how it works is not really very clear but it can be effective. However, as with the topical agents, the relief is only temporary and regular treatment is required to keep the hyperhidrosis at bay. Patients may often then choose to buy a machine at home to carry this on permanently and the dermatology nurses at Orpington often recommend a brand or supplier of repute.
Botox injections – this involves multiple injections into the sites involved and often requires quite a dedicated and committed patient as it is painful and treatment is potentially lifelong. Again, the benefits are temporary (6-9 months in the first instance) but this can reduce with subsequent treatments. Botulinum toxin-A (BTX-A) is the most commonly used version and it inhibits release of a neurotransmitter called acetylcholine temporarily from the nerve terminals. Side effects include dry eyes, flu-like symptoms and compensatory sweating elsewhere on the body. It can, however, be extremely effective with a reported 75-100% reduction in sweat after application.
[Naumann MK, Hamm H, Lowe NJ; Botox Hyperhidrosis Clinical Study Group. Effect of botulinum toxin type A on quality of life measures in patients with excessive axillary sweating: a randomized controlled trial. Br J Dermatol 2002; 8: 247-52.]
Can’t I just take a tablet and be done with?
There are some oral preparations which can be taken but none are licensed in the UK for use in primary hyperhidrosis. These include glycopyrrolate, oxybutynin and propantheline bromide which are all oral anticholinergic agents. They can be effective and are often used, at the dermatologist’s discretion, if other measures have been used and failed or if the hyperhidrosis is widespread and severe enough for the patient to tolerate the side effects. These include a severe dry mouth, dry eyes and inability to pass urine (urinary retention).
What about surgery?
This is called endoscopic thoracosympathectomy (or cutting a band of sympathetic nerves within the chest) and is performed, clearly, under general anaesthetic by an experienced specialised vascular surgeon. It is permanent but it is reserved for those in whom all else has failed. The main side effect is compensatory hyperhidrosis (ie sweating elsewhere on the body) and if this occurs it is also permanent and therefore, patients should be counselled carefully before undergoing the procedure. I have yet had a patient who has gone for this as a treatment and I have seen one patient who underwent the procedure many years ago for palmo-plantar hyperhidrosis and has now been left with irreversible compensatory hyperhidrosis of the face.
Dr Sandy Flann, Consultant Dermatologist