Sun Solutions
Many people know about sunlight and its potentially harmful effect on skin. Scientists believe the sun causes 90% of the aging of the skin, in addition to cancer and decreased immunity. Sun worshippers put themselves at risk following repeated sunburns and exposure in tanning salons. A tan is produced when ultraviolet radiation stimulates the melanocytes in the germinating skin layer to produce more melanin and oxidize the melanin already there. Both processes serve as the body's attempted protective mechanisms by diffusing and absorbing additional ultraviolet radiation. Your body only needs about 20 minutes of sun per day to produce enough vitamin D which helps your immune and cardiovascular systems. Too much however, decreases the body's immune system and the harmful effects of ultraviolet (UV) radiation is the primary cause of skin aging, wrinkling, hyperpigmentation and skin cancer. One person dies every four hours from skin cancer yet, if detected early, there is a 95% cure rate.
Acute Sun DamageWhen severe sun damage occurs, inflammatory pathways of the skin are activated. Releasing of prostaglandins leads to vasodilation (blood vessel dilation) and edema (swelling). Increased blood flow to the affected skin begins in about 4 hours and peaks between 8-24 hours after sun exposure. Sunburn or severe ultraviolet exposure results in erythema (redness), pain and potential long-term sun damage. Even without erythema or redness, sun exposure can be harmful.
Chronic Sun DamageRepeated exposure to UV radiation leads to fragility and hemorrhage of blood vessels and eventually to sagging and wrinkling of the skin. There also is loss of skin elasticity. The elastin fibers in your skin are like little rubber-band-like strands beneath your skin which, when they break down, never regain their strength and elasticity. Collagen fibers are similarly affected. You may not see the effect for 20-30 years but the damage is cumulative and permanent. There may also be other changes including abnormal pigmentation, increased vulnerability to bruising because of thinning of the walls of blood vessels supplying the skin, and carcinogenic changes leading to cancer.
Sun damage begins within 7 minutes of sun exposure--even sooner if a person is on diuretics, retinols, antibiotics, or has certain medical conditions. There are two main types of ultraviolet (UV) radiation, UVA and UVB rays. UVB causes skin redness, commonly called sunburn. UVA has a longer wave length, burns deeper, and many think is more likely to cause cancer although both rays can do this. UVA rays weaken the body’s ability to protect itself by decreasing the skin immunity and changing DNA, thus increasing the risk for cancer. UVB can also induce skin cancer, as well as cause premature aging of the skin causing wrinkling, epidermal hyperplasia, and damage to elastic and collagen fibers. Impaired vision can also result from damage to the retina, lens, and cornea, and also cause cataracts.
Abnormal pigmentationSolar lentigines, also called sun or age spots, are hyperpigmented patches commonly seen in the exposed areas, such as the face and hands.
CarcinogenesisRepeated intense ultraviolet (UV) light exposures, especially multiple sunburns, are a major risk factor for skin cancer, including malignant melanoma, the most deadly form. Skin cancer is the most common form of cancer in the U.S. Sunlight plays a role in the formation of atypical nevi, which also are considered a risk factor for melanoma. A changing mole is the most common sign of malignant melanoma. It is estimated that 2000 cases of melanoma develop in Michigan every year.
Physicians use the ABCDE criteria for the signs of early melanoma, which are as follows:
Actinic keratoses result from sun damage and 10-15 percent evolve into skin cancer. Of the three most common types of skin cancer, the most common is basal cell carcinoma (85%). The most strongly linked to sun exposure is squamous cell carcinoma (10%). The most likely to metastasize and the most deadly is malignant melanoma (5%). < previous | next > | print page | home | back to top | contact us |
