About Skin and Sun Problems
However, the positive aspects of being out in the sun appear miniscule in comparison to the negative effects that sun has on our skin. Some of these harmful effects are listed below:
- The immediate effects of exposure to sun include sunburn, rashes and aggravation of pre existing skin conditions.
- A little more exposure can cause photo damage and photo ageing. Prolonged sun exposure can lead to development of actinic keratosis, a skin condition which may lead to skin cancers like basal cell cancer, squamous cell cancer and melanomas.
- Due to the effect of UV light, the outer layer of skin called ‘epidermis’ is damaged resulting in fine wrinkles. This skin can be easily injured causing bruising. Areas like the back of the neck are thickened (cutis rhomboidalis nuchae) and develop stiff wrinkles.
- Tanning, which is actually skin burn, can damage the elastic tissue of the skin leading to freckles, speckled pigmentation, brown spots (solar lentigo) and small white spots also called as age spots.
- The small blood vessels, especially of the face, are dilated and appear as telengiectasiae.
- All these changes ultimately cause premature ageing of the skin.
Chances of sun damage increase considerably in people working outdoors. Travelling to places near the equator or at high altitude increase the risk of exposure to UV light. Similarly, water, sand and snow multiply the damage to skin due to sun manifolds as they tend to reflect the sun rays.
Ultra Violet Light
UV light is the harmful component of the sun rays. It can be classified into two components based on their wavelengths. They are:
- UVA light (320-400nm): It forms 95% of UV light. It is strong enough to reach the lower layer of the skin. It is responsible for maximum damage to skin causing sun burns, pre cancerous changes and signs of ageing. Its level in the sun rays remains constant all along.
- UVB light (290-320 nm): It does not possess enough penetrating power and affects only the superficial layers of the skin. It is required by the body for producing vitamin D but when it is more than the optimal levels required by the body, it can cause skin cancers.
Sunscreens as a protection from UV light
The purpose of using a sunscreen is to protect the skin from the UV light. The sunscreens may be available as a physical barrier to reflect back the UV light, e.g., sun glasses and film screens or in the form of a chemical barrier which absorbs the UV light and converts it into heat, e.g., lotions, creams or sprays to be applied on areas exposed to sunlight. All sunscreens have an SPF or sun-protection factor which is a measure of the protection offered by the sunscreen against sunburn.
The sunscreens that were developed earlier offered protection only against UVB light. They promoted a false sense of security among people who were prompted to increase their stay in the sun after applying these sunscreens. This caused prolonged exposure to UVA light. Now, several ‘broad spectrum sunscreens’ have been developed which are intended to block both the UVA and the UVB light.
Important factors to be considered in a sunscreen
When choosing a sunscreen, one should examine the following points carefully:
- Does the sunscreen protect you adequately?
- Is it to heavy on your skin?
- Does it suit your skin type?
The SPF mentioned on a sunscreen measures only the protection it has to offer against the UVB light. It has nothing to do with the sunscreens ability to block the harmful UVA light responsible for the signs of ageing on the skin. So it is not the correct way to decide the efficacy of the sunscreen. One should choose a sunscreen on the basis of its contents.
Benzophenone compounds such as avobenzone (Parsol-1789) and an element known as octocrylene can be grouped under the broad spectrum sunscreens. They offer protection against both UVA and UVB light. Another compound called ecamsule has been established to possess significant UVA blocking properties. It is present in a product called Anthelios SX.
Titanium dioxide and/or zinc oxide and MexorylÂ® when present in the sunscreen, provide protection against the UVA light. These compounds have a longer sun- shielding effect as well because they do not disintegrate in the presence of UV light. Therefore they stay put on the skin for a longer duration of time. They are especially beneficial to people who tend to sweat a lot or spend more time in or near water.
Sunscreens with extremely refined zinc or titanium
Nowadays, sunscreens with extremely refined zinc or titanium are available in the market. They are so sheer that they are almost invisible despite retaining their protective properties against UV rays.
Sunscreens containing tretinoin (Retin-A, Renova, etc) are unsuitable for a dry skin. It is better to use a sunscreen which combines tretinoin with a moisturizer in a cream base (Retisol-A) for such skin types.
For a sunscreen to be absorbed properly by the skin and for optimal results, it is best to apply the sunscreen at least half an hour before stepping out in the sun. It is better to buy a sunscreen that suits one’s skin and is not too heavy. A product that is not very comfortable to put on results in decreased usage defeating the entire purpose of buying the product. While applying the sunscreen it is not enough to apply a thin coat. One should apply a generous coat of the sunscreen to effectively block the UV rays. It should be reapplied every two hours or every time after wiping off the skin, swimming or profound sweating. These days, water resistant and perspiration resistant sunscreens are also available in the market though they also do not work indefinitely and have to be reapplied after certain duration of time.
One should also be careful to see whether the chemicals present in the sunscreen are agreeable to the skin. If pimples or rashes break out on the skin after applying the sunscreen, then that sunscreen is definitely not for you.
Using a good sunscreen in an appropriate manner and as a matter of routine goes a long way in reducing the signs of ageing and protecting the skin from other harmful effects of UV rays.