From this pharmacy CPD module you will learn about:
- The structure of the skin
- The role of emollients in contact irritant dermatitis
- Types of emollients and their main ingredients
- The fire risk associated with paraffin-based emollients
Download this module - this includes the 5 minute test - here.
Presentations to the pharmacy for dry skin on the hands will have increased over the last few weeks as patients take measures to curb the spread of COVID-19. Frequent handwashing and the use of alcohol sanitisers strip the skin of moisture and leave it dry, sore, red and in severe cases, fissures can develop where the skin has cracked. This condition is known as irritant contact dermatitis and is a form of eczema.
Emollients are a well known and effective treatment for dry skin conditions, including irritant contact dermatitis.(1) When applied correctly they play a vital role in re-establishing healthy, intact skin.(2)
Providing advice on the correct treatment and helping patients wade through the large selection of over-the-counter emollients is an important role for pharmacy teams. The British Association of Dermatologists has issued a statement on dry skin and frequent handwashing to reduce COVID-19 risk, the main details of which are outlined below.
The structure of the skin
The skin is the body’s largest organ. It is a protective barrier against pathogens and helps to maintain body temperature. The skin is made up of three layers:
- Epidermis – this is the outmost layer of the skin, made up of four layers:
- Stratum corneum (corneal layer) – protects the body against invading pathogens and irritants. It is composed of highly organised intercellular lipid matrix, and corneocytes (flattened cells filled with keratin). Corneocytes contain various substances that hold water. The structure can be described as the ‘bricks and mortar’ of the skin with the corneocytes representing the ‘bricks’ and lipids as the ‘mortar’.(3)
- Granular cell layer – secretes substances to keep the epidermal barrier intact.
- Spinous or prickle-cell layer – plays a role in immune responses of the skin.
- Basal cell layer – new cells grow from this layer.
- Dermis – the middle layer of the skin. This layer provides a variety of functions including sweat regulation and oil production. It is the location of the hair follicles, blood vessels and nerve endings.
- Subcutaneous fat layer – this fat layer helps to regulate body temperature and connects the dermis to the muscles and bones.(4)
The cumulative effect of constant handwashing and chronic exposure to irritants and chemicals such as soaps and alcohol can disrupt the stratum corneum and allow penetration of irritants into the deeper layers of the skin. This initiates immunological reactions such as inflammation. Increased water loss from the skin leads to dryness, itching and cracking. Skin pH can also become altered. Skin is normally an acidic pH but elevation in pH causes corneocytes to adhere less tightly.(3)
Emollients in the treatment of contact irritant dermatitis
Emollients are a mainstay of treatment for irritant contact dermatitis. They contain a variety of ingredients that form an oily layer on the surface of the skin. This prevents water loss from the stratum corneum, keeping it hydrated. Furthermore, histamine release is reduced and lipid synthesis is stimulated helping to reduce inflammation.
There are a number of emollient formulations including creams, lotions, soap substitutes and ointments. There is no ‘best’ emollient as patient preference can vary. Ultimately, if a patient likes a product, they will use it more often and it will therefore be more effective.
Generally, oil-based products are more effective at replenishing the skin’s moisture but are less popular due to the lasting greasy residues on the patient’s skin. A combination of products may be necessary where a ‘lighter’ product can be applied during the day and a thicker, more moisturising product applied at night. Smaller sized products can be conveniently carried around by the patient for use throughout the day to allow for maximum applications of the emollient.
Types of emollient
There are many different emollient formulations available, each containing a number of different ingredients. Understanding the differences between them will facilitate appropriate selection for your patient. Ideally, the emollient will provide water to the stratum corneum and enough oil to prevent loss of hydration.
An emulsion of oil in water. Lotions contain more water than oil so are less moisturising than creams. They spread easily and so are useful for hairy areas or when quick absorption is required. Examples include E45 lotion and Aveeno lotion.
Another emulsion of water and oil with a higher oil content than lotions. These are thicker and more moisturising than lotions. They are not greasy and are suitable for daytime use. Examples include E45 cream, Aveeno cream, Diprobase cream and Oilatum cream.
Often a cosmetically unacceptable product for most as these are stiff and greasy, although they provide an excellent barrier on the skin to prevent water loss and so aid skin barrier repair. They are particularly useful for dry, thick, scaly areas. Patients may consider using these at night. Examples include Diprobase ointment, Epaderm ointment, liquid & white soft paraffin (50%/50%) BP and QV intensive ointment.
An alternative to traditional soaps, these are effective at cleansing while helping to prevent further drying of the skin and reducing itching. They do not elevate the skin's pH as traditional soaps do and do not contain fragrances and detergents, which can dry and irritate the skin. Patients should be advised that soap substitutes do not foam up as traditional soap products do but can be reassured that with correct handwashing technique, they are as effective at cleansing. Examples include E45 emollient wash cream, QV gentle wash and Aquamax cream wash.(5,6)
When selecting an emollient, it is useful to know the different ingredients to aid selection most appropriate for your patient.
- Water is often one of the first ingredients listed for the emollient.
- Occlusives such as petroleum are the oil component that blocks the evaporation of water. Petroleum is one of the best occlusives at holding in water. Other occlusive include cetyl alcohol (a fatty alcohol), lanolin, lecithin, mineral oil, paraffin (liquid paraffin, white soft paraffin, yellow soft paraffin) dimethicone and stearic acid.(7)
- Humectants such as propylene glycol, lactic acid, urea and glycerol draw water into the epidermis from the dermis. Preparations containing urea may sting if applied to fissured skin. They are almost always used with occlusive ingredients to prevent excessive loss of water from the deeper layers of the skin.(7)
- Antimicrobials such as benzalkonium chloride and chlorhexidine hydrochloride may be added. Long-term use can cause sensitisation in some patients. Dermol cream is an emollient containing an antimicrobial.
- Oatmeal is contained in the Aveeno range for its anti-itch properties.
The use of the ingredient sodium lauryl sulphate (SLS) has been reviewed in recent years. It is a detergent and surfactant, which helps to maintain the creamy consistency of emollients. SLS is mainly found in aqueous cream and emulsifying ointments. Studies have found that SLS use has been associated with skin reactions such as redness, stinging, itching and burning. It is therefore not recommended that products containing SLS are used as leave-on emollients.(8)
When recommending an emollient for dry hands, advise patients on the correct method of application:
- Recommended a soap substitute for hand washing, use tepid water and pat hands dry after.
- Apply emollient following hand washing frequently, every few hours if possible.
- Apply the emollient gently in the direction of the hair growth. Vigorous rubbing may block hair follicles, causing inflammation (folliculitis) and trigger itching.
- Apply to all areas of the hands, not just dry patches.
- An ointment may be used at night if a heavier emollient is required. Cotton gloves may be applied after application to prevent bedclothes getting greasy.
- Emollient use should be continued after skin has improved to prevent flare-up if continuous handwashing is still being practised.
Risks associated with paraffin-based emollients
There is a risk of severe and fatal burns from fires caused by the build-up of residues on bedclothes and fabrics from emollients containing paraffin. The emollient itself is not flammable but acts as an accelerant, increasing the speed of ignition and intensity of the fire when fabric with residue dried on it is ignited.(9)
The Medicines and Healthcare products Regulatory Agency (MHRA) initially issued an alert in 2007 on this risk when using emollients containing more than 50% paraffin but recent data shows that even products with less than 50% paraffin have been associated with fatal burns. There may even be a risk with paraffin-free emollients. Advise patients not to smoke or go near naked flames as bedding or clothing that has been in contact with emollient can quickly ignite. More information can be found on the gov.uk website.
- National Eczema Society (2019) Emollients factsheet.
- British Journal of Nursing (2013) The vital role of emollients in the treatment of eczema.
- DermNet NZ (2018) Barrier function in atopic dermatitis.
- AtopicDermatitis.net (2017) How does atopic dermatitis affect the skin and body?
- NHS Health A-Z (2017) Emollients.
- National Eczema Society (2018) Emollients factsheet.
- Harvard Medical School: Harvard Health Publishing (2019) Moisturizers: do they work?
- British Association of Dermatologists Position statement on the place of bath emollients in the treatment of atopic dermatitis.
- Medicines and Healthcare products Regulatory Agency Drug Safety Update (2018) Emollients: new information about risk of severe and fatal burns with paraffin-containing and paraffin-free emollients.