Hyperhidrosis (excessive sweating)

Hyperhidrosis describes abnormally excessive sweating.

What is this skin condition?

Hyperhidrosis describes abnormally excessive sweating. But what is an abnormal amount? Researchers have tried to define excessive based on the normal distribution of sweat volume, measured by collecting sweat using filter paper in the axillae (underarm). The filter paper is weighed dry and then again after 1 hour of sweating. The problem with this is that sweating is a very personal thing with some people wanting little to no sweating and others being very tolerant of sweat.

Essentially, if the patient perceives it as a problem then it is a problem. The approach of the NHS to sweating is highly variable which wide variation in the availability of certain services.

The first important consideration in hyperhidrosis is to determine if the problem is

1. Localised  (small areas i.e. hands only, axillae only) or

2. Generalised ( widespread). If it is widespread this could suggest an underlying problem  (although often does not). If you have developed generalised sweating then further investigation is needed. If you have generalised sweating you should see your GP as occasionally medications, hormonal problems such as thyroid disease or other systemic diseases can lead to increased sweating.

Localised underam sweating hardly ever has an underlying cause and the problem is simply finding a solution. Local sweating at non-underarm sites such as the face or hands rarely has a cause but effective treatments are generally prescription only and a visit to the GP will be needed.

Why have I got it?

The main reason for sweating is temperature regulation and we all sweat when we get hot. The other condition to produce sweating is anxiety or stress. The evolutionary reason for this is that in many stressful situations you get hot and need to cool down. Stress induced sweating gives you a head start on the cooling. There are areas in the brain that control these functions and there is a large spectrum of normal.  A small proportion of people have clearly abnormal sweating levels and the cause for this is unclear. Genetics will play a role and many patients with local hyperhidrosis report a family history. Exactly which genes and molecular signalling pathways are involved remains unclear.

Sweating occurs when a nerve impulse arrives in a sweat gland. This triggers the release of a chemical called acetyl choline which leads to sweating. The interruption of acetyl choline is a key part of some treatments for hyperhidrosis.

 

Comparing the treatment options.

The treatments vary depending on which body sites are affected.

Self –treatment

The first goal is to work out if you really do have a problem. Sweating to some degree is normal. Are there ways to minimise stress or anxiety? Is your work environment simply to hot?

There are many different anti-perspirants  available and it is worth trying a few different ones.

For underarm sweating you can purchase absorbant pads. Specialised inner soles are also available from simply feet .

For facial sweating glycopyronium wipes are available . However, you should see your GP for this problem first before embarking on self treatment.

From your GP

Your GP will be able to prescribe stronger antiperspirants. These contain alluminum salts and work by blocking the sweat glands. They are best applied at night to completely dry skin. Application to wet skin will trigger irritancy. Products include Anhydrol Forte , Driclor.

Tablets that reduce sweating can be prescribed by your GP although this is more commonly done by a Dermatologist.

From a Dermatologist

Tablets: Anti-cholinergic tablets block the chemical signal, acetyl choline, that triggers sweating. These tablets can be very effective but do have side effects, the most common one being a dry mouth. If too many tablets are taken other problems can include blurred vision, constipation and drowsiness.

Three different tablets can be tried. Propantheline is the only drug licensed for treatment of sweating. Oxybutynin and glycopyronium bromide are not specifically licensed for sweating but can be used. Glycopyronium bromide (Robinul) often produces less side effects but is harder to obtain in the UK. Some NHS pharmacies import Robinul from the US for use in NHS patients although due to expense the use of this drug is limited.

Botox: Botulinum toxin prevents the release of the chemical acetyl choline. Botox acts in a small area around the injection site which makes it safe to use in the skin. Multiple injections in the underarm area are a highly effective way to reduce or stop sweating. Some NHS clinics will offer Botox but in many parts of the UK, Botox for sweating is now excluded from NHS services. The cost of the drug alone for the standard dose of 100U Botox  for each  axilla (50units x2) is approximately  £130. The price at a private clinic, including all overheads, equipment,  nurse time and the fee for the Doctor performing the procedure should be no more than £500.

Botox has been used to treat sweating at other sites such as the palms. Due to the pain from the injections, nerve blocks are generally needed which increases the time and expense.   Temporary weakness of the small muscles of the hand is a definite risk.

Iontophoresis. This treatment involves a small electric current being passed through the skin. Hands or feet are place in water baths and a small controlled electrical current is passed though the hands.  A short term but effective reduction in sweating is seen in most patients LINK pubmed. It is excellent or hands and feet.  Underarms respond less well due to the reduced conductivity throught  the axillary pads that are used. Masks for facial iontophoresis are now available although the effectiveness has not been studied much in formal trials. Once a patient has been trained , if the iontophoresis is successful, the patients will generally need to buy their own machine.

A patient receiving iontophoresis for palmar sweating.

miraDry. miradry is a new treatment involving microwave technology. Following local anaesthetic the miraDry probe is placed over the treatment area and sweat glands are heated and destroyed. There have not been many publications in peer reviewed journals but it does defintely seemt to work well for some people. The number of clinics offering miraDry in the UK remains small. Click here to visit their website for further details.

Other helpful sources of information include

http://www.hyperhidrosisuk.org/

http://www.iontophoresis.info/

 

 


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