The Sun and Your Skin

Transcription

1 The Sun and Your Skin Karla S. Rosenman MD Park Nicollet Dermatology Skin Anatomy Skin Anatomy 1

2 Sunlight Ultraviolet (UV) radiation is carcinogenic to humans, causing all major types of skin cancer. UV-emitting tanning devices are also classified as carcinogenic to humans based on their association with skin and ocular melanoma cancers. 2

3 UVA: Aging Wrinkles Brown spots White spots Dilated blood vessels Up to 90% of the visible changes commonly attributed to aging are caused by the sun. UVA: Aging 3

4 UVB: Burning UVB: Burning UVA Penetrates Deeper 4

5 DNA Damage UVB damages DNA directly UVA damages DNA indirectly via free radicals and reactive oxygen species Window Glass UVA passes through window glass UVB is blocked by window glass Variability UVA is fairly constant all day and all year UVB is strongest during the summer at mid-day 5

6 UV Index UV index Indicates the strength of solar UV radiation Reported on a scale of Take care when the UV index is 5-6 or higher. Sun Exposure Contrary to popular belief, 80% of a person's lifetime sun exposure is not acquired before age 18; only about 23% of lifetime exposure occurs by age 18. Lifetime UV Exposure in the United States Ages Average Accumulated Exposure* percent percent percent percent *Based on a 78 year lifespan How To Protect Yourself SLIP on a shirt SLOP on sunscreen SLAP on a hat SEEK shade SLIDE on sunglasses 6

7 SLIP on a shirt Sun protective clothing Coolibar ( Solumbra ( White T-shirt has an SPF 7 Coolibar Retail Store 2401 Edgewood Ave South Suite 400 Minneapolis, MN Store Hours Monday-Friday: 9:00 AM 5:00 PM Saturday & Sunday: Closed Customer Service: service@coolibar.com SLOP on sunscreen SPF 30 or greater 1 ounce per full-body application A shot-glass full 1/3 to ¼ tsp for the face Average bottle 8oz. Reapply every 2 hours or after swimming/sweating 7

8 SLAP on a hat A wide-brimmed (3-inch or greater) hat covers places where it is difficult to apply sunscreen, i.e., the scalp, the tops of the ears, and the back of the neck. When you re wearing a hat, your face has more protection than with sunscreen alone. A hat will shade your eyes, protecting its delicate internal structures and keeping you from squinting in the sun. SEEK shade Especially during mid-day when UVB rays are strongest SLIDE on sunglasses Sun exposure is related to cataracts, eyelid cancers, and macular degeneration. Look for sunglasses that absorb and/or block percent of both UVA and UVB light. 8

9 Avoid Tanning Beds Tanning beds emit both UVA and UVB First exposure to tanning beds before age 35 increases melanoma risk by 75%. People who use tanning beds are 2.5x more likely to develop squamous cell carcinoma and 1.5 times more likely to develop basal cell carcinoma. More on Sunscreen Physical Sunscreens Minerals Reflect sun Less likely l to cause allergic reactions Broad-spectrum Titanium dioxide Zinc oxide 9

10 Chemical Sunscreens Absorb sun Oxybenzone Avobenzone (Parsol 1789) = good UVA blocker Ecamsule (Mexoryl) = good UVA blocker Chemical Sunscreens Sun Protection Factor (SPF) Measures UVB protection SPF = amount of UV to burn with sunscreen amount of UV to burn without sunscreen No universally accepted measurement of UVA protection 10

11 SPF SPF 30 is not twice as good as SPF 15 SPF 15 ~94% blockage SPF 30 ~97% blockage SPF 60 ~98% blockage SPF 85 ~99% blockage Recent study indicates a higher SPF may compensate for under-application of sunscreens. Environmental Working Group Annual Sunscreen Guide 11

12 Environmental Working Group Annual Sunscreen Guide Oxybenzone (Benzophenone-3) A common chemical sunscreen. It does get absorbed through the skin. It can cause allergic contact dermatitis. One study found that higher maternal exposures are associated with a decrease in birth weight for girls and an increase in boys. It may have an estrogen-like activity. Probably best avoided before puberty. Retinyl Palmitate A vitamin A derivative. EWG recommends avoiding it based on: The preliminary data from one study performed at the FDA 1-year study of approximately 70 mice exposed to UVA/UVB for 4 hours a day EWG interpreted the data as: Tumors and lesions developed 11 to 21% sooner in the mice treated with topical vitamin A cream (at concentrations of 0.1% to 0.5%) than in control animals treated with a vitamin-free cream. 12

13 Tretinoin A vitamin A derivative. Brand name: Retin-A Am J Clin Dermatol. 2005;6(4): ; ( ) Long-term efficacy and safety of tretinoin emollient cream 0.05% in the treatment of photodamaged facial skin: a two-year, randomized, placebocontrolled trial. 204 subjects, ½ applied tretinoin 0.05% daily for 2 years. Findings: Decreased sun damage. No increase in skin cancers. 13

14 Vitamin D Made in response to UVB radiation Other sources Fortified milk (100 IU/cup), cereal, and bread Fish, egg yolk, and liver Cod liver oil 1360 IU/serving Salmon 794 IU/serving Supplements Vitamin D The ideal Vitamin D level is controversial. Vitamin D levels are difficult to measure and measurements can vary significantly from lab to lab. 14

15 Vitamin D Darker pigmented skin makes less vitamin D Elderly skin makes less vitamin D Serum vitamin i D levels l are lower in obese people Vitamin D Toxicity Mainly from supplements Nausea, vomiting, poor appetite, constipation, weakness, weight loss High blood calcium -> confusion, heart rhythm abnormalities Tolerable upper intake for adults: 4000 IU/day 15

16 Vitamin D Sun exposure is not a reliable way to get Vitamin D. Sun exposure is known to increase skin cancer. The safest and most reliable way to get Vitamin D is supplementation. Vitamin D 1000 IU daily for adults. True or False? You can get sunburned on a cloudy day. True or False? You can get sunburned on a cloudy day. TRUE! 80% of the sun s rays pass through the clouds 16

17 True or False? You only need to wear sunscreen when you are at the beach. True or False? You only need to wear sunscreen when you are at the beach. FALSE! Also remember Sand reflects 25% of sun s rays. Snow reflects 80% of sun s rays. Th t t t t d th f 30 The sun s rays penetrate water to a depth of 30 inches. 17

18 True or False? Sunscreen Sunscreen with a SPF of LESS than 15 is enough to protect my skin. SPF 8 True or False? Sunscreen Sunscreen with a SPF of LESS than 15 is enough to protect my skin. SPF 8 FALSE! True or False? My skin doesn t get sunburned, so I don t need to worry about protecting myself from overexposure to the sun. 18

19 True or False? My skin doesn t get sunburned, so I don t need to worry about protecting myself from overexposure to the sun. FALSE! Sunburn Treatment Cool soaks Ibuprofen Topical steroid cream (hydrocortisone 1%) Topical aloe gel Drink water Seek Medical Treatment If: Severe pain Severe blistering Confusion Nausea & vomiting Fainting 19

20 Skin Cancer The most common form of cancer in the US. 1 in 5 Americans will develop some form of skin cancer during their lifetime. More than 20 Americans die each day from skin cancer, primarily melanoma. Malignant Melanoma In ,720 new cases of melanoma 8,650 deaths from melanoma Melanoma accounts for about 3% of skin cancer cases, but it causes more than 75% of skin cancer deaths. Lifetime risk 1 in 50 for Whites 1 in 1000 for Blacks 1 in 200 for Hispanics Malignant Melanoma Most common cancer year-old age group 2nd most common cancer in year-old age group Risk factors: Red or blonde hair Blue or green eyes >50 moles, large moles or atypical moles 1 st degree relative with melanoma Previous diagnosis of melanoma History of other cancers 20

21 A: Asymmetry B: Borders 21

22 C: Color D: Diameter E: Evolving 22

23 Non-Melanoma Skin Cancer Basal cell carcinoma Squamous cell carcinoma About 90% of non-melanoma skin cancers are associated with exposure to ultraviolet (UV) radiation from the sun. Basal Cell Carcinoma The most common form of skin cancer. Squamous Cell Carcinoma The second most common form of skin cancer. 23

24 Thank you! Karla S. Rosenman MD Park Nicollet Dermatology