SINGAPORE - The skin has its own natural moisturising factors, such as lipids and ceramides, to increase and retain its moisture.
But these decrease with age, sun exposure and too-frequent bathing, said Dr Wong Soon Tee, a dermatologist at Mount Elizabeth Novena Hospital.
He said the underlying cause of a person's dry skin can also be traced to his age.
Children with dry skin may have ichthyosis (a group of genetic skin disorders characterised by the presence of excessive amounts of dry surface scales) or atopic eczema, the most common form of eczema, which causes sensitive and inflamed skin.
Age-related skin changes contribute to the dry skin observed in the elderly population, he added. For others, dry skin may be due to environmental or lifestyle factors.
For example, skin is driest in wintry weather. Air-conditioned places would also dry out the skin.
Others who wash their hands frequently, such as nurses and hairstylists, or those who use harsh soaps and detergents, would have their skin's moisture depleted.
Dr Wong said dermatologists rarely treat dry skin with oral medication, though they advise patients to drink enough fluids.
But "over-drinking does not reverse dry skin", he pointed out.
"Although there are many products in the market, including bird's nest, that claim to address dry skin, there is very limited data in Western medical literature to substantiate such claims."
In fact, very few foods have "significant and direct impact on the skin complexion", said Dr Wong, as food is usually broken down into fatty acids, amino acids and basic sugar units before they are absorbed by the body.
People with dry skin should instead know the importance and correct use of moisturisers, which provide a sealing effect to keep water from escaping from the skin.
They should use moisturisers several times a day and after taking showers, when the skin is moist and better able to trap water.
Patients with dry skin and more serious skin diseases - such as atopic eczema, ichthyosis or psoriasis (a chronic skin condition characterised by itchy, red patches of skin covered with silvery scales) - may be prescribed medical-grade moisturisers, said Dr Wong.
In general, avoid taking long, hot showers and using harsh, drying soaps. Go for gentle skin cleansers and shower gels and stay out of the sun to minimise sun damage, he added.
This article was first published on July 03, 2014. Get a copy of Mind Your Body, The Straits Times or go to straitstimes.com for more stories.