Dry skin or xerosis is probably one of the most common skin problems in the world. It is even more so in persons above the age of 65yrs (70% or more).
Xerosis is more bothersome in winter season because of the decreased temperature & humidity in the environment. Urbanisation & development in countries has lead to further aggravation of this problem because of increased use of air conditioners & heaters, in day to day living & working conditions. What these appliances do is, that they reduce the humidity in the atmosphere thus causing more ‘Drying’of the skin.
Dry skin is essentially a dehydration of the uppermost layers of the skin i.e the stratum corneum.Whether ‘Inherent Xerosis’ is due to water loss from the skin or a disorder in the sebum production has not yet been accurately determined. Conversely stripping off of the sebum (lipid layer) of the skin or insufficient fluid intake is known to worsen xerosis leading to ‘environmental dependent xerosis’. Normal skin has an outer layer – stratum corneum, which is composed of neatly arranged corneocyte cells in a parallel configuration. In cases of xerosis, this surface layer gets disorderly, the individual cells become uneven with some, projecting over the surface thus giving the skin a scaly appearance & a dry rough ‘feel’. These changes are induced by exposure to cold dry winds & in case of a decreased humidity. So also, solvents,soaps, detergents, etc ‘strip off’ the protective lipid layer of the skin. The above mentioned causative factors, damage the cutaneous barrier of the skin leading to : – increased evaporation of water i.e upto 75 times normal, from the skin. – allows for entry of irritants or allergens through the skin leading to inflammation & pruritus (itching).
Xerosis is a broad term , a state of the skin. When coupled with other manifestations it can lead to:
– Atopic dermatitis – a common childhood affliction seen from infancy onwards. It is a complex combination of xerosis alongside systemic & immunological variations leading to a plethora of visualised changes. This condition encompasses so many different views & factors that it merits an article by itself.
– Keratosis Pilaris – seen in childhood & young adults is a localized form of xerosis, restricted to follicular openings.
– Hand Eczema, Plantar dermatosis – are variations of xerosis with additional irritant or allergic dermatitis thrown in !
– In the Elderly, xerosis is particularly bothersome. There is severe dryness of the skin leading to ‘itchiness’. Rubbing & scratching provoke inflammation, secondary infection & eczematization. Such severe cases are termed as ‘ Asteatotic eczema’ or ‘Winter Itch’.
THERAPY :
All therapeutic measures are aimed at replenishing the moisture content of the skin & more importantly keeping ‘in’ the water, albeit temporarily at least, so as to allow time for the skin to heal itself. Treatment is subdivided into Preventive measures & therapy of pre existing dermatosis.
– Preventive therapy necessitates a regulation of the living & working Environments wherein use of ‘Humidifiers’ is encouraged. Room temperature should be so maintained so as to be comfortable.
– Excessive bathing with very hot water is to be discouraged. It is recommended to use lukewarm water for bathing & preferably concomitant use of bath additives such as oils, salts etc. Soap free substitutes are to be encouraged.
– Frequent use of emollients is a must. An emollient acts as a barrier against evaporation of water from the skin. For best results it should be used ‘immediately’ after a bath . What happens is that during the bath the skin corneocytes absorb water, causing them to swell up & give the skin a smoother look. Immediate application of a moisturiser prevents this water from evaporating thus maintaining the skin suppleness for a longer time. It soothes the skin, allowing it to heal from within. This should be complimented by a proper intake of nutrients & supplements so as to facilitate the healing process.
If skin dryness is minimal then a ‘oil in water’ based moisturiser is sufficient, but in severe cases thicker ‘water in oil’ bases such as vaseline, petroleum jelly etc are indicated.
– Excessive exposure to soaps, disinfectants, cleaners, solvents etc should be avoided.
– Clothing such as woollens, synthetics which can cause mechanical trauma are to be avoided.
Treatment of Pre existing xerosis is fairly simpler.
– As mentioned in preventive factors, the skin should be soaked in lukewarm water with additives like bath oils, colloidal oatmeal to supply further lubrication. Soap substitutes should be used to cleanse the skin to keep it bacteria free as well as to prevent excessive drying up.
– Hydrophobic substances such as moisturisers should be used as per the doctor’s orders, so that the water is ‘kept’ in the skin & transepidermal water loss is prevented.
– Eczematous areas need to be treated with topical steroid ointments with or without occlusive dressing.
– If emollients are not sufficient then it calls for a further attack with agents called ‘Humefactants’. These are chemicals that affect the desquamation of the skin, corneocyte adhesion & promote hydration . These include ‘Alpha Hydroxy’ acid – Lactic acid, glycolic acid & Urea preparations.
– Oral preparations like Anti Histamines & at times even steroids are necessary in a number of cases. These should be used under strict Medical supervision only.
The myriad preparations & formulations used for dry skin are so plentiful that a Dermatologist can easily be in a quandry as to which preparation to prescribe. It requires a lot of dedication on behalf of both the Patient & the doctor to undertake this journey through the realms of ‘ Dryness ‘ into the spring of ‘Suppleness’.
