  
|  |
|
| Moisturisers and moisturising bath additives or washes |
|
|
Reviewed by Dr Victoria Lewis, specialist registrar in dermatology
|
Why do I need to use moisturisers?
Our understanding of the structure and function of the skin is
something that has improved in recent years, and it is now widely accepted that
using moisturisers regularly is the most crucial thing you can do to keep your
eczema under control.
Normal healthy skin has a high water content and is flexible and
elastic. Layers of lipid (oil) in the surface layer of skin, called the stratum
corneum, prevent water evaporating from the deeper layers of skin. The outer
layer of cells contain a natural water-retaining substance that holds water in
the cells, making them swell and press tightly against one another so there are
no cracks. The epidermis is said to provide a barrier function, since it
prevents foreign substances entering and excessive moisture being
lost.
In atopic eczema the normal barrier function of the skin is
disturbed, possibly as a result of genetic changes. The layers of lipid in the
stratum corneum are not formed normally, and this means that water can more
readily evaporate from the skin’s surface. This allows the cells in the stratum
corneum to dry out. When they dry out they shrink, and cracks form between the
cells. This further reduces the ability of the skin to retain moisture, and the
skin surface cracks as it dries out, allowing allergens, irritants and
micro-organisms to penetrate more easily.
This means that the biggest solution to eczema is to use regular
moisturisers to rehydrate and help restore the barrier function of the skin.
This in turn reduces itching and scratching, and prevents the penetration of
allergens and irritants, thereby reducing their ability to trigger
inflammation. It also reduces the ability of micro-organisms to penetrate the
skin and cause infection.
Regular use of moisturisers helps prevent flare-ups of eczema
and has also been shown to reduce the need to use
topical corticosteroids.
Why do I need to use moisturising bath additives?
Not only can soaps be irritants themselves, but washing with hot
water and soap strips the skin of its surface layer of natural oils. This means
that unless you replace the oil by using a moisturiser after washing, water
evaporation from the skin increases and after washing the skin is drier than it
otherwise would have been. To combat this problem you should try and minimise
your use of soap when washing, and instead use soap substitutes. Products such
as aqueous cream and emulsifying ointment can be used as soap substitutes for
hand washing or when bathing.
Moisturising bath additives are also useful because they replace
the layer of oil on the skin when you emerge from the bath. You should bathe in
water that is not too hot for no more than 10 minutes. You should then pat the
skin dry after using them so you don’t rub off the oil.
How do moisturisers work?
There is a vast, almost overwhelming array of different
moisturisers available in today’s marketplace. They contain numerous different
ingredients, but most work in one or more of the following ways.
Occlusive moisturisers
Contain oils such as liquid paraffin (also known as mineral
oil), white soft paraffin, yellow soft paraffin, wool fat (also known as
lanolin), coconut oil, or emulsifying wax. These work by providing a layer of
oil on the surface of the skin that prevents water evaporating from the skin
surface. This increases the water content of the cells in the stratum corneum,
which swell against each other thereby reducing cracks in the skin surface. The
oils may also penetrate into the stratum corneum where they act like the
natural lipids found in healthy skin and prevent water evaporating from the
deeper layers of skin. Oils may be mixed with various amounts of water to
produce moisturisers with different properties, ie lotions, creams or
ointments. By their very nature they will not absorb fully into the skin and
may make clothes greasy, but they are very effective, particularly if applied
overnight.
Humectant moisturisers
Contain ingredients such as urea, glycerin, lactic acid,
glycolic acid, or sodium pyrrolidone carboxylate. These penetrate into the
stratum corneum where they attract and retain water, thereby increasing the
capacity of the skin to retain water. They are particularly useful for very dry
skin.
Keratolytics
At higher concentrations urea, lactic acid and glycolic acid
also act as keratolytics. They are used to break down a skin protein called
keratin. In conditions such as chronic eczema and ichthyosis, excessive amounts
of keratin cause the skin cells to harden, making the skin become thickened and
scaly. Keratolytics break down the keratin in the hardened and thickened skin,
helping to shed skin cells from these areas, and soften and improve the
appearance of dry, scaly skin. This action also improves the ability of
moisturising ingredients to penetrate the skin and rehydrate it. Allantoin is
also a keratolytic.
Various other ingredients may be added to moisturisers. Listed
below are some you may come across, together with their action.
-
Benzalkonium chloride is an antiseptic/antimicrobial.
-
Chlorhexidine hydrochloride is an
antiseptic/antimicrobial.
-
Dimeticone (also known as silicon fluid) is a water-repellent
substance that is used in barrier creams to help protect the skin.
-
Isopropyl myristate, cetyl alcohol and stearyl alcohol have
moisturising properties.
-
Lauromacrogols have properties of local anaesthetics. When
applied to the skin they soothe and relieve itching.
-
Phenoxyethanol is an antimicrobial preservative.
-
Sorbic acid has an antibacterial effect.
-
Zinc oxide is used for its soothing, astringent and antiseptic
effects on the skin.
-
Preservatives such as benzyl alcohol and hydroxybenzoates
(parabens) are needed to prevent the growth of micro-organisms when water is
included in the product.
-
Various other ingredients are used to modify the consistency
and stability of moisturising products.
Which type should I use?
The many moisturisers available today come in various different
formulations. Knowing the difference between lotions, creams and ointments is
important in helping you choose the products that are most appropriate for your
skin. The type of moisturiser you choose to use will depend on the area of body
you are treating and the degree of dryness and scaling of the skin.
Lotions
Mixtures of oil in water and are light, non-greasy
formulations that have a cooling effect. They are easily absorbed and good for
mildly dry skin and weeping eczema. They are also particularly suitable for
hairy areas of skin, such as the scalp or chest.
Creams
Creams are also mixtures of oil in water but are slightly
thicker than lotions. They are generally non-greasy and easily absorbed into
the skin and are often preferred to ointments for this reason.
Ointments
Thick, occlusive oil-based moisturisers that are best for very
dry areas of skin, though many people don’t like them as they find them too
greasy.
There is no ‘right’ moisturiser for everyone. It may take a bit
of trial and error to find the moisturisers that suit you best, but it is worth
persevering until you find products that you are comfortable with, because
otherwise you are unlikely to use them regularly.
Using a combination of different moisturising formulations, as
well as moisturising bath additives and soap substitutes when you wash, will
often provide maximum rehydration for the skin and help restore its barrier
function. For example, you may prefer to use a lighter lotion or cream during
the day and apply a thicker ointment at night, and likewise use a lighter
non-greasy product on the face and a more greasy ointment on areas of very dry
skin.
It is worth bearing in mind that certain ingredients of
moisturisers can irritate eczema if your skin is sensitive to them. This is
rare, but the following list covers ingredients that may potentially cause
irritation. If you have had a patch test that indicates you are allergic to one
of these you should check the ingredients of your moisturisers and topical
medicines and avoid using products that contain them.
-
Beeswax
-
Benzyl alcohol
-
Butylated hydroxyanisole
-
Butylated hydroxytoluene
-
Cetostearyl alcohol (including cetyl and stearyl
alcohol)
-
Chlorocresol
-
Edetic acid (EDTA)
-
Ethylenediamine
-
Fragrances
-
Hydroxybenzoates (parabens)
-
Imidurea
-
Isopropyl palmitate
-
N-(3-Chloroallyl)hexaminium chloride (quaternium 15)
-
Polysorbates
-
Propylene glycol
-
Sodium metabisulphite
-
Sorbic acid
-
Wool fat and related substances including lanolin (many
products now contain purified versions of wool fat, which have reduced the
problem).
What moisturisers are available?
The following is a list of some of the moisturisers currently
available in the UK, together with their ingredients.
| Name of moisturiser |
Ingredients |
| . |
. |
| |
Urea, white soft paraffin, maize starch, isopropyl
myristate, syncrowax HR-C, palmitic acid, sorbitan monolaurate, arlatone G |
| |
Emulsifying ointment, phenoxyethanol (or other
antimicrobial depending on manufacturer), purified water |
| |
Colloidal oatmeal, glycerin, allantoin, water,
distearyldimonium chloride, petrolatum, isopropyl palmitate, cetyl alcohol,
dimeticone, benzyl alcohol, sodium chloride |
| |
Urea, lauromacrogols, dimethicone, phenyl dimeticone,
liquid paraffin, cetylpalmitate, stearic palmitic acid, octyldodecanol,
glycerol, polysorbate, carbomer, trometamol, benzyl alcohol, purified
water |
| |
Urea, lactic acid, glyceryl monostearate, betaine
monohydrate, diethanolamine cetylphosphate (Amphisol), hard fat, cholesterol,
sodium chloride, purified water |
| |
White soft paraffin, light liquid paraffin, emulsifying
wax, cetyl stearyl alcohol, glycerin, butylparaben, methylparaben,
ethylparaben, propylparaben, phenoxetol, citric acid, purified water |
| |
Dimeticone, wool fat, glycerol, isopropyl myristate,
sorbic acid, cetyl alcohol, polysorbate 60, sorbitan monostearate, purified
water |
| |
White soft paraffin, liquid paraffin, fractionated coconut
oil, butane 40 |
| Dermol cream | Liquid paraffin, isopropyl myristate, benzalkonium chloride,
chlorhexidine dihydrochloride, cetostearyl alcohol, glycerol, cetomacrogol
1000, phenoxyethanol, disodium phosphate dodecahydrate, sodium dihydrogen
phosphate dihydrate, purified water |
| |
Liquid paraffin, isopropyl myristate, benzalkonium
chloride, chlorhexidine hydrochloride, cetostearyl alcohol, cetomacrogol 1000,
phenoxyethanol, purified water |
| |
Liquid paraffin, white soft paraffin, chlorocresol,
cetomacrogol, cetostearyl alcohol, phosphoric acid, sodium dihydrogen
phosphate, purified water |
| |
White soft paraffin, liquid paraffin |
| Doublebase gel | Liquid paraffin, isopropyl myristate, glycerol, carbomer, sorbitan
laurate, triethanolamine, phenoxyethanol, purified water |
| |
Light liquid paraffin, white soft paraffin, hypoallergenic
anhydrous lanolin, empilan GMS, cetyl alcohol, sodium cetostearyl sulphate,
carbomer, methyl hydroxybenzoate, propyl hydroxybenzoate, sodium hydroxide,
citric acid monohydrate, purified water |
| |
Urea, lauromacrogols, dimethicone, phenyl dimethicone,
liquid paraffin, cetyl palmitate, stearic palmitic acid, octyldodecanol,
glycerol, polysorbate, carbomer, tromethamine, benzyl alcohol, purified
water |
| | Light liquid paraffin, cetomacrogol, white soft paraffin,
hypoallergenic anhydrous lanolin, glyceryl monostearate, isopropyl palmitate,
hydroxybenzoates (parabens), benzyl alcohol |
| |
Emulsifying wax, white soft paraffin, liquid paraffin |
| |
Emulsifying wax, yellow soft paraffin, liquid
paraffin |
| |
Urea, benzyl alcohol, light liquid paraffin, sodium
lactate solution, magnesium stearate, microcrystalline wax, triglycerol
diisosterate, isopropyl palmitate, wool alcohols, magnesium sulphate, purified
water |
| |
Urea, benzyl alcohol, elfacos ST 9, elfacos E200, sorbitan
isostearate, PEG-2 hydrogenated castor oil, ozokerite, arlacel 582, PEG-7
hydrogenated castor oil, light liquid paraffin, isopropyl palmitate, medium
chain triglycerides, octyldodecanol, glycerol, sodium lactate solution, lactic
acid, magnesium sulphate, dimeticone, purified water |
| Gammaderm cream | Evening primrose
oil, beeswax, hydroxybenzoates (parabens), propylene glycol |
| |
Sodium pyrrolidone carboxylate, liquid paraffin, isopropyl
myristate, sodium lactate, cetomacrogol, emulsifying wax, myristyl myristate,
cetomacrogol 1000 BP, hydroxybenzoates (parabens), phenoxyethanol, purified
water |
| | Yellow soft paraffin, emulsifying wax, liquid
paraffin |
(also
sometimes known as oily cream) |
Wool alcohols ointment, phenoxyethanol, dried magnesium
sulphate, purified water |
| |
Cetostearyl alcohol, macrogol cetostearyl ether, liquid
paraffin, white soft paraffin, methyl parahydroxybenzoate, sodium citrate
anhydrous, citric acid anhydrous, purified water |
| |
Urea, glycerol monostearate, octyl palmitate, myristyl
lactate, mineral oil, promulgen D (contains Cetearyl alcohol and ceteareth-20),
propylene glycol, propyl parahydroxybenzoate (E216), methyl parahydroxybenzoate
(E218), purified water |
| |
Light liquid paraffin, white soft paraffin, PEG 1000
monostearate, cetostearyl alcohol, glycerol, potassium sorbate, benzyl alcohol,
citric acid monohydrate, povidone K29/32, purified water |
| |
White soft paraffin, liquid paraffin, stearyl alcohol,
polyoxyl 40 stearate [E431], carbomer, sodium hydroxide, methylparaben [E218],
propylparaben, [E216], disodium edentate [E463], purified water, citrus-rose
perfume oil |
| |
Purified water, white soft paraffin, cetostearyl alcohol,
polysorbate 40, propylene glycol, glycerol monostearate 40 – 50, liquid
paraffin, medium-chain triglycerides, sorbic acid, colloidal anhydrous silica,
sodium hydroxide |
| |
White soft paraffin (white petroleum jelly) |
| |
Yellow soft paraffin (yellow petroleum jelly) |
What moisturising bath oils are available?
The following is a list of some of the moisturising bath
additives and washes currently available in the UK, together with their
ingredients.
| Name of bath oil |
Ingredients |
| . |
. |
| |
Liquid paraffin, lanolin oil, oxybenzone, perfume,
PEG-4-dilaurate |
| |
Colloidal oatmeal, liquid paraffin, sunflower seed oil,
dioctyl adipate, PEG-40 sorbitol hexaoleate, silica, cera alba, parfum,
triclosan, PEG-5 cocomonium methosulfate, ascorbyl palmitate, tocopheryl
acetate |
| |
Colloidal oatmeal, liquid paraffin, citric acid, sodium
bicarbonate, calcium silicate, ascorbic acid, tocopheryl acetate, laureth-4,
dimethicone, ethylcellulose |
| |
Soya oil, polyoxyethylene lauryl ether (4mol EO), oleic
acid diethanolamide, perfume oil DV5171, propylene glycol, butylated
hydroxytoluene, ascorbyl palmitate, citric acid monohydrate |
| |
Soya oil, mixed lauromacrogols, liquid paraffin,
quaternium-18 hectorite, butylated hydroxytoluene, ascorbyl palmitate, citric
acid, propylene glycol, perfume oil |
| Cetraben emollient bath additive | Light liquid paraffin, C-12-13-Pareth-3, medium chain
triglycerides |
| |
Liquid paraffin, acetylated wool alcohols, isopropyl
myristate, macrogol 3 lauryl ether |
| |
Liquid paraffin, isopropyl myristate, benzalkonium
chloride, chlorhexidine hydrochloride, cetostearyl alcohol, cetomacrogol 1000,
phenoxyethanol, purified water |
| |
Liquid paraffin, isopropyl myristate, benzalkonium
chloride, sorbitan monostearate, polysorbate 60, IMS 95%, purified water |
| |
Light liquid paraffin, isopropyl myristate, laureth-4 |
| |
Liquid paraffin, cetyl dimethicone, C12-13 pareth-3 |
| |
Liquid paraffin, petrolatum, cera microcristallina,
synthetic wax, carnauba, zinc oxide, laureth-4, C12-13 pareth-3, cetyl
dimethicone, aluminium stearate, stearic acid |
| |
Liquid paraffin, isopropyl myristate, benzalkonium
chloride, sorbitan stearate, polysorbate 60, industrial methylated spirit 95%,
methylthioninium chloride, purified water |
| |
Light liquid paraffin, isopropyl myristate, C12-C14
alcohol with 3 molecules of ethylene oxide, polyol fatty acid ester, iso-octyl
stearate |
| |
Light liquid paraffin, acetylated lanolin alcohols,
isopropyl palmitate, polyethylene glycol 400 dilaurate, polyoxyethylene 40
sorbital septaoleate, floral spice |
| Oilatum fragrance free |
Light liquid paraffin, acetylated lanolin alcohols,
isopropyl palmitate, polyethylene glycol 400 dilaurate, macrogol ester |
| |
Light liquid paraffin, benzalkonium chloride solution,
triclosan, acetylated lanolin alcohols, isopropyl palmitate, oleyl alcohol,
polyoxyethylene lauryl ether |
| |
Light liquid paraffin, polyethylene 617A 2-octadodecanol,
polyethylene glycol 400 dilaurate, polyoxyethylene 40 sorbital septaoleate,
polyethylene glycol-2-myristyl ether propionate, polyphenylmethyl siloxane
copolymer, floral spice |
Can I get them on prescription or do I have to buy
them?
Although you can buy moisturisers and bath additives from your
local chemist, your doctor can also prescribe them for you. Depending on
whether or not you pay for your prescriptions, it may be preferable for you to
ask your doctor to prescribe your moisturisers. If you do pay prescription
charges some products are cheaper to buy, and your pharmacist will usually
advise you if this is the case.
How often should I moisturise and how much should I
use?
It is important that you apply moisturisers liberally and
regularly (at least twice a day) to prevent the skin drying out. Many people
with eczema do not use enough moisturiser. This is a shame, since regular use
of moisturisers, even when your skin is not bad, can help prevent flare-ups of
eczema and reduce the need to use topical corticosteroids.
Moisturisers are most effective when they are applied to moist
skin, for example following a bath or shower, but they should also be applied
at other times, perhaps three or four times throughout the day depending on how
dry your skin is. Particularly dry skin may benefit from an application of
greasy moisturiser every couple of hours. To make this easier you could ask
your pharmacist to supply you with a small container in which to carry small
quantities of moisturiser with you during the day.
Sweat can irritate your eczema, so after exercising you should
have a cool shower to rinse and soothe the skin and then apply moisturiser.
Chlorine in swimming pools can also aggravate eczema, so again it is important
to rinse off with a shower immediately after swimming and then apply
moisturiser to soothe the skin.
So how much should you use? Basically you should apply your
moisturisers liberally. For example, an adult with widespread eczema could be
using around 500g of moisturiser or more per week, and a child around 250g. As
a general rule of thumb, for most people, the quantity of moisturiser that you
use should be about 10 times the quantity of topical corticosteroid you
use.
|
|
Based on a text by Helen Marshall, pharmacist
|
Last updated 28.08.2007
|
 |
|
|
 |
| |      |
|
