Archive | July 2024

Part II July UV Safety Month. Prevent Sunburn and Types of Photosensitivity!

The three types of Ultra Violet radiation are classified according to their wavelength.

They differ in their biological activity and the extent to which they can penetrate the skin. The shorter the wavelength, the more harmful the UV radiation. However, shorter wavelength UV radiation is less able to penetrate the skin.

The Ultra Violet region covers the wavelength range 100-400 nm and is divided into three bands:

UVA (315-400 nm)
UVB (280-315 nm)
UVC (100-280 nm).

Short-wavelength UVC is the most damaging type of UV radiation. However, it is completely filtered by the atmosphere and does not reach the earth’s surface.

Medium-wavelength UVB is very biologically active but cannot penetrate beyond the superficial skin layers. It is responsible for delayed tanning and burning; in addition to these short-term effects it enhances skin ageing and significantly promotes the development of skin cancer. Most solar UVB is filtered by the atmosphere.

The relatively long-wavelength UVA accounts for approximately 95 per cent of the UV radiation reaching the Earth’s surface. It can penetrate into the deeper layers of the skin and is responsible for the immediate tanning effect. Furthermore, it also contributes to skin ageing and wrinkling. For a long time it was thought that UVA could not cause any lasting damage. Recent studies strongly suggest that it may also enhance the development of skin cancers.

Treatment: One is prevention and avoid sun light when it is out the strongest in ultra-violet rays 12pm to 3pm and always use sunscreen.

Polymorphic light eruption (PLE) is the most common form of immunologically mediated photosensitivity dermatoses. Exposure to sunlight in spring or summer results in an irritable rash that resolves within a few days, providing further exposure is avoided.

The following treatments may reduce the severity of PLE:

Topical corticosteroid creams to relieve symptoms
Short course of oral steroids, eg to cover a summer holiday
Hydroxychloroquine
Phototherapy: UVB narrowband UVB, or PUVA for several weeks in early spring.

Are there any other health issues related to UV radiation?

In addition to cancer, exposure to UV rays can cause other health problems. UV rays, either from the sun or from artificial sources like tanning beds, can cause sunburn. In some people, exposure to UV rays can cause a rash or a type of allergic reaction. Exposure to UV rays can also cause premature aging of the skin and signs of sun damage such as liver spots, actinic keratosis, and solar elastosis.

UV rays can also cause eye problems. They can cause the cornea (on the front of the eye) to become inflamed or burned. They can also lead to the formation of cataracts (clouding of the lens of the eye) and pterygium (tissue growth on the surface of the eye), both of which can impair vision.

Exposure to UV rays can also weaken the immune system, so that the body has a harder time fending off infections. This can lead to problems such as reactivation of herpes triggered by exposure to the sun or other sources of UV rays. It can also cause vaccines to be less effective.

Some medications can make you more sensitive to UV radiation, making you more likely to get sunburned. Certain medical conditions can be made worse by UV radiation.

About UV rays and vitamin D

Doctors are learning that vitamin D has many health benefits. It might even help lower the risk for some cancers. Your skin makes vitamin D naturally when it is exposed to UV rays from the sun. How much vitamin D you make depends on many things, including how old you are, how dark your skin is, and how strong the sunlight is where you live.

At this time, doctors aren’t sure what the optimal level of vitamin D is. A lot of research is being done in this area. Whenever possible, it’s better to get vitamin D from your diet or vitamin supplements rather than from exposure to UV rays because dietary sources and vitamin supplements do not increase skin cancer risk, and are typically more reliable ways to get the amount you need.

Remember tips about UV rays for men and women:

Men, especially those with lighter skin, are more likely than anybody else to get skin cancer, including melanoma—the deadliest kind of skin cancer.

When you think about sun protection, you might think about a day at the beach. But over your lifetime, you get sun exposure doing everyday things like biking, working, running, or even mowing the lawn. Sun exposure is the main source of ultraviolet (UV) rays, which can cause skin cancer. And UV exposure adds up over time, increasing your risk of developing skin cancer.

Men tend to get more sun exposure than women. Men spend more time outside over their lifetimes than women, and they’re more likely to work outdoors than women. Women’s personal care products, like moisturizer and makeup, often contain sunscreen, while many products for men don’t.

About one-third of U.S. adults get sunburned each year. Sunburn, which can increase your risk of getting skin cancer, is common among white men, young adults, and men who tan indoors. When outside on a sunny day for more than an hour, only about 14% of men use sunscreen on both their face and other exposed skin.

Seek shade, especially during midday hours. This includes 10 am to 4 pm, March through October, and 9 am to 3 pm, November through February. Umbrellas, trees, or other shelters can provide relief from the sun.

Wear a long-sleeved shirt and pants or a long skirt for additional protection when possible. If that’s not practical, try wearing a T-shirt or a beach cover-up.

Apply a thick layer of broad spectrum sunscreen with an SPF of 15 or higher at least 15 minutes before going outside, even on cloudy or overcast days. Reapply sunscreen at least every 2 hours and after swimming, sweating, or toweling off.

Indoor and outdoor tanning often begin in the teen years and continue into adulthood. Don’t wait to teach your children about the dangers of tanning. Children may be more receptive than teens, so start the conversation early, before they start outdoor tanning or indoor tanning. For example, you can Discourage tanning, even if it’s just before one event like prom. UV exposure adds up over time. Every time you tan, you increase your risk of getting skin cancer. Help preteens and teens understand the dangers of tanning so they can make healthy choices.

There is no such thing as a safety tan!!!!

QUOTE FOR MONDAY:

Jul1

“Most skin cancers are caused by too much exposure to ultraviolet (UV) rays. Most of this exposure comes from the sun, but some can come from man-made sources, such as indoor tanning beds and sun lamps. People who get a lot of exposure to UV rays are at greater risk for skin cancer.

The main types of UV rays that can affect your skin include UVA rays and UVB rays. UVB rays have more energy and are a more potent cause of at least some skin cancers, but both UVA and UVB rays can damage skin and cause skin cancer. There are no safe UV rays”

American Cancer Society (https://www.cancer.org/cancer/risk-prevention/sun-and-uv/uv-protection.html)

Part I July UV Safety Month. Prevent Sunburn and Types of Photosensitivity!

Jul1

The Sun is by far the largest object in the solar system. It contains more than 99.8% of the total mass of the Solar System (Jupiter contains most of the rest).

It is often said that the Sun is an “ordinary” star. That’s true in the sense that there are many others similar to it. But there are many more smaller stars than larger ones; the Sun is in the top 10% by mass. The median size of stars in our galaxy is probably less than half the mass of the Sun. A process called fusion heats the Sun. Fusion happens in the core of the Sun. It is very hot there. In fact, the core’s average temperature is around 27,000,000 degrees Fahrenheit. The surface of the Sun is cool compared with the core, only 10,000 degrees Fahrenheit.

This fusion process not only heats the Sun, it makes the sunlight we see here on Earth. This sunlight travels the speed of light which is 186,282 miles per second or 299,792,458 meters per second. This means the light from the Sun takes 8.4 minutes to travel 93 million miles to Earth. If the world’s fastest land animal were to travel that same distance, it would take a cheetah over 151 years to reach the Earth running about 70 mph nonstop!

Ultraviolet radiation: Invisible rays that are part of the energy that comes from the sun. Ultraviolet radiation can burn the skin and cause skin cancer.

Ultraviolet radiation is made up of three types of rays — ultraviolet A, ultraviolet B, and ultraviolet C. Although ultraviolet C is the most dangerous type of ultraviolet light in terms of its potential to harm life on earth, it cannot penetrate earth’s protective ozone layer. Therefore, it poses no threat to human, animal or plant life on earth.

Ultraviolet A and ultraviolet B, on the other hand, do penetrate the ozone layer in attenuated form and reach the surface of the planet. Because ultraviolet A is weaker than ultraviolet B, scientists long blamed ultraviolet B as the sole culprit in causing skin cancer in persons with a history of sunburn and repeated overexposure to ultraviolet radiation. Recent research, however, has also implicated ultraviolet A as a possible cause of skin cancer.

Photosensitivity refers to various symptoms, diseases and conditions caused or aggravated by exposure to sunlight.

A rash due to photosensitivity is a photodermatosis (plural photodermatoses).
If the rash is eczematous, it is a photodermatitis.
A chemical or drug that causes photosensitivity is a photosensitiser.
A phototoxic reaction to a photosensitiser results in an exaggerated sunburn reaction and no immune reaction is involved.
A photoallergic reaction to a photosensitiser results in photodermatitis and is due to delayed hypersensitivity reaction.
A photoexacerbated condition describes a flare of an underlying skin disease on exposure to sunlight.

Photosensitivity is characterized into many groups:

Polymorphic light eruption (PLE):

PLE generally affects adult females aged 20–40, although it sometimes affects children and males (25%). It is particularly common in places where sun exposure is uncommon, such as Northern Europe, where it is said to affect 10–20% of women holidaying in the Mediterranean area. It is less common in Australasia. It has also been reported to be relatively common at higher altitudes compared to sea level.

PLE can occur in all races and skin phototypes and may be more prevalent in skin of colour than in white skin. There is a genetic tendency to PLE, and it is sometimes associated with or confused with photosensitivity due to lupus erythematosus (which generally is more persistent than PLE).

Some patients experience PLE during phototherapy, which is used to treat skin conditions such as psoriasis and dermatitis.

There are three types of UV rays:

Ultraviolet A (UVA): UVA rays penetrate deep into the layers of the skin and lead to premature signs of aging, which include fine lines and wrinkles. It is important to note that the amount of UVA stays relatively consistent throughout the year, and exceeds the amount of UVB in both summer and winter. Even on a cloudy day, 80% of the sun’s UVA rays pass through the clouds and reach our skin and eyes. It’s also important to know that tanning beds work by emitting primarily UVA rays.

Ultraviolet B (UVB): UVB rays are the primary cause of sunburn, thickening of the skin, and several types of skin cancers – including melanoma. UVB rays penetrate the outermost layer of skin and cause damage to skin cells. UVB also can cause damage to eyes and the immune system.

Ultraviolet C (UVC): UVC is the strongest of the UV spectrum radiation. Fortunately, UVC rays do not reach the earth’s surface because it is blocked by the ozone layer of the atmosphere. The only way we can be exposed to UVC radiation is from an artifical source, such as a lamp or laser. UVC rays can cause severe skin burns and eye injuries even when exposed for only a few seconds. Since the penetration depth of UVC rays is very low, these injuries usually resolve within a week with virtually no risk of long-term health risks (skin cancer, cateracts, vision loss).

Causes:

Genetic factors may be important with many affected individuals reporting a family history of PLE. Native Americans have a hereditary form of PLE (actinic prurigo).

PLE is caused by a delayed hypersensitivity reaction to a compound in the skin that is altered by exposure to ultraviolet radiation (UVR). UVR leads to impaired T cell function and altered production of cytokines in affected individuals. There is a reduction in the normal UV-induced immune suppression in the skin. This has been suggested to be either due to oestrogen or deficiency of vitamin D.

The rash is usually provoked by UVA (in 90%). This means the rash can occur when the sunlight is coming through window glass, and that standard sunscreens may not prevent it. Occasionally, UVB and/or visible light provoke PLE.

PLE may be a rare occurrence in the individual concerned or may occur every time the skin is exposed to sunlight. In most affected individuals, it occurs each spring, provoked by several hours outside on a sunny day. If further sun exposure is avoided, the rash settles in a few days and is gone without a trace within a couple of weeks. It can recur next time the sun shines on the skin. However, if the affected area is exposed to more sun before it has cleared up, the condition tends to get more severe and extensive with longer to heal.

Stay tune tomorrow for part II on Ultralight rays from the Sun to Sunburn and Types of photosensitivity for some!