Sun exposure and negative effects on the skin

Prolonged sun exposure has been a significant and consequential issue for quite some time. Even moderate exposure to unprotected skin can be detrimental to your skin’s health. The days of slathering on vegetable oil and literally baking in the sun are over. However, our bodies do need some sun – just moderate amounts. The sun is an excellent source of Vitamin D, but it doesn’t take that much exposure to obtain this benefit. Consistent exposure to the sun’s ultraviolet rays can cause significant damage to your skin, eyes, and immune system. Ultraviolet (UV) rays are invisible to the eye and are absorbed through your skin. UV light has the ability to harm the DNA (our genetic makeup) in your skin.

Most people associate tanned skin with healthy skin. However, tanning from the sun or tanning booth causes acceleration of the ageing process and increases the risk of skin cancer. The ultraviolet rays of the sun focus on fibres in the skin known as elastin. Elastin is a key extracellular matrix protein that is critical to the elasticity and resilience of many vertebrate tissues including large arteries, lungs, ligaments, tendons, skin, and elastic cartilage.1 As the fibres break down, sagging and stretching of the skin ensues, and the ability for it to snap back into place is compromised. This damage is done over time and does not show up immediately. Non-melanoma skin cancer is much less prevalent in African Americans, those from the Middle East area, and Asians.

Extended Sun Exposure Consequences

  • Precancerous and cancerous skin conditions or lesions. Moles or nevi can appear anytime throughout our life. Most moles or birthmarks are typical; however, some may be larger or irregular. Such atypical moles can indicate the formation of melanoma.

  • Immune system suppression. Exposure to UV radiation is immunosuppressive.2 The immune system’s function is suppressed, and the skin then becomes compromised by the inability to defend against foreign bodies.

  • Freckling and discoloration of the skin. The pigment of the skin can change to develop darker spots or solar lentigos. Fair complexions are especially prone to freckling from birth. Age spots develop over time due to UV exposure. Guttate Hypomelanosis is characterised by small white spots. Red areas on the neck are known as Poikiloderma of Civatte. Yellow discolouration, or sallowness, can occur as well.

  • Blood vessel changes such as dilation can cause recurring bruising of the skin known as telangiectasias.

  • Breakdown of elastic and collagen tissue (elastosis) causes sagging and compromises the elasticity of the skin.

  • Cataracts of the eye. They are a form of eye damage in which the lens of the eye clouds vision. Cataracts can lead to blindness if left untreated; however, eye surgery can correct cataracts. Pterygium is skin cancer around the eyes, and degeneration of the macula can occur as well. Wearing sunglasses that offer UV protection is a way to avoid these issues.

  • Premature ageing of the skin. Premature ageing can cause the skin to become thick, wrinkled, and leathery in look. It develops over time after many years of sun exposure. Visible changes to the skin are commonly associated with exposure to the sun. Skin texture changes can occur on the back of the neck (cutis rhomboidalis nuchae) and thinning of the skin causes wrinkles, bruising, and skin tearing, most notably on the forearms and back of the hands. Premature ageing from the sun can be prevented with the proper protection.

  • Actinic keratoses. Actinic keratoses (AKs) are common skin lesions heralding an increased risk of developing squamous cell carcinoma (SCC) and other skin malignancies, arising principally due to excessive ultraviolet (UV) exposure.3These skin lesions occur on the areas of the body that are typically exposed to the sun such as the face, hands, forearms, chest, and neck. Examine your skin for raised, reddish, growths that are rough in texture and see a medical professional as soon as possible.

The ozone layer around the earth has been depleting as each year goes by. This results in less atmospheric protection from ultraviolet radiation and major and minor skin issues. It’s been noted that one in five Americans will develop skin cancer, and one individual succumbs to the disease every hour. The primary reason for the development of this cancer is unprotected exposure to UV radiation.

The prevalence of skin cancer continues to increase significantly. Delving deeper into the different types of skin cancer can arm you with the necessary knowledge to protect yourself and prevent detrimental skin conditions.

Basal cell carcinoma (nonmelanoma) is defined as the abnormal growth of lesions and is known as the most common and frequently recurring type of skin cancer. The lesions are characterised as red patches, pink, smooth bumps, or scars and can be found anywhere on the body. These normally occur as a result of occasional, intense sun exposure. Basal cell carcinomas are the most common type of skin cancer tumours. Basal cell carcinoma develops very slowly over time, and it does not often spread to other parts of the body. It can, however, penetrate to the bone and cause considerable damage. A variety of treatment modalities exist and are selected based on recurrence risk, importance of tissue preservation, patient preference, and extent of disease.4

Squamous cell carcinoma, also referred to as nonmelanoma or tumours’, look like firm, red nodules or scaly flat lesions that may bleed if picked. Both basal cell and squamous cell cancers are the least serious and make up the majority of all skin cancers. When treated early, they are most likely curable and don’t metastasise or spread. Squamous cell carcinoma can develop into large masses and can spread to other areas of the body.

Melanoma, made up of abnormal skin pigment cells called melanocytes, is the most serious form of skin cancer. Although melanoma represents a small subset, it is the most deadly cutaneous neoplasm and is an increasingly common malignancy affecting a younger population than most cancers.5 The average range of ages in those who typically develop melanoma is 15-29 years old, essentially affecting adolescents and young adults. If not treated in time, it can metastasise to other organs. Melanoma is not always related to exposure to the sun—possible immune system disorders can be a contributing factor. Melanoma is often characterised by a patch or bump that can be either red or white in colour. It can look like a regular mole, but the symmetry is typically irregular. About one in 74 Americans will be diagnosed with melanoma with the median age at diagnosis of 57 years.6
The ABCDE rule keeps tabs on new and existing lesions while keeping any changes in check:

Asymmetry – the shape of the lesion or birthmark is not round, but instead, irregular in shape.
Border – the edges are cloudy or obscured.
Colour – can be a combination of brown, black, tan, red, white, or blue in a random pattern.
Diameter – any significant changes in the size of moles or existing birthmarks.
Evolving – New lesions or moles that appear and changes colour, shape, or size.

Ultraviolet light emanates from tanning beds as well, so it’s important to stay away from them. Also, be aware that you are still exposed to UV rays from the sun in the winter because they are prominent during the daylight hours. It’s essential to wear sunscreen year round no matter the season to protect yourself.

Numerous risk factors for the development of melanoma have been identified, including white skin, fair hair, light eyes, sun sensitivity, tendency to freckle, family history of melanoma, dysplastic nevi, increased numbers of typical nevi, large congenital nevi and immunosuppression.7

Summary of those at risk:

  • Very fair complexions with freckles, light eyes, and red hair that burn easily.

  • Those who’ve had incidents of severe sunburns during their teen years.

  • Family history, genetic, or hereditary factors.

  • Chronic, long-term sun exposure due to having a job outdoors every day.

  • Having skin cancer in the past increases the likelihood of recurrence.

UVB rays often lead to sunburn affecting the superficial layer of the skin, while UVA rays are absorbed in the deeper layers. When UV rays enter skin cells, they interfere with the fragile processes that affect the skin’s growth and appearance. It’s important to know that the sun’s rays are strongest between the hours of 10 AM and 4 PM. When there’s snow on the ground, UVB rays can reflect and bounce back a majority of the rays hitting the skin repeatedly.

As stated by Dr. Stephen I. Katz, director of NIH’s National Institute of Arthritis and Musculoskeletal and Skin Diseases,

“When you’re exposed to ultraviolet radiation, there’s a repair process that goes on constantly in each one of your exposed cells”. However, as the body naturally ages, the skin’s ability to repair itself continues to lessen.

- Dr. Stephen I. Katz -

Preventative Measures

Even if you were an avid sunbather when you were younger, it’s still beneficial to start implementing preventative measures. Obviously, the earlier you begin to protect yourself, the better off you’ll be. Parents should always apply SPF 30 or higher to children 20 minutes before any kind of sun exposure. It also needs to be reapplied every two hours, especially when swimming or perspiring. Sun exposure in childhood and having more than one blistering sunburn in childhood are associated with an increased risk of melanoma.8

The increasing incidence of skin cancers and photo damaging effects caused by ultraviolet radiation has increased the use of sun screening agents, which have shown beneficial effects in reducing the symptoms and recurrence of these problems.9Sunscreens should never be used after the expiration date due to the compromised efficacy of the compound contained within. The use of high sun protection factor (SPF) sunscreens has also been widely promoted for the prevention of skin cancer, including melanoma.10Sunscreens are undoubtedly effective in preventing sunburn, yet their ability to prevent skin cancer, especially melanoma, is currently under considerable debate.11

Choose your clothing wisely. There are many types of clothes that have UV protection built in. Women should choose the appropriate makeup that contains SPF for the face. As stated previously, some brands of sunglasses provide 100% UV protection for your eyes. Sit under an umbrella or wear a hat that will provide shade for your face.

Steer clear of tanning beds as they produce the same kind of UV radiation. In 2006 the International Agency for Research on Cancer (IARC), the cancer research arm of the World Health Organization (WHO), responded to the alarming increase in skin cancer incidence and the rising popularity of tanning beds by producing a landmark evidence-synthesis report on the dangers of artificial UV exposure and skin cancer.12Unfortunately, the use of tanning beds has not significantly decreased.

Examine your entire body and take note of changes in existing birthmarks or moles and lesions that have just appeared. If you are especially prone to sunburn, it’s a good idea to get checked by a dermatologist at least once a year.

Conclusion

It’s been proven that intense exposure to the sun results in numerous skin conditions including skin cancer. The development of skin cancer is not immediate but grows slowly over time. Behaviours throughout your life will determine the severity or likelihood of detrimental skin conditions. Baby boomers tend to be at the highest risk because of previous sunbathing practices as young adults. It was not prominently known at the time that the sun’s rays could negatively affect the skin. Only now are they noticing effects such as premature ageing. Risk factors include genetic predisposition, fair complexions, history of sun exposure, sun protection practices, and chronic exposure every day. The most common types of skin cancer are basal cell carcinoma and squamous cell carcinoma. These cancers are treatable and highly curable if diagnosed in time. Melanoma is the most serious type and can be fatal. The ozone layer continues to deteriorate, so it’s important to implement appropriate sun protection measures to prevent the development of the disease and other adverse and questionable skin problems. The days of lounging poolside in the sun covered in baby oil are over!


References and Sources:

  1. Mithieux, S.M. and Weiss, A.S. (2005). Elastin. Advances in Protein Chemistry, 70: 437–461. Retrieved from http://www.sciencedirect.com/science/article/pii/S0065323305700139.
  2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2661262/.
  3. Dodds, A., Chia, A., and Shumack, S. (2014). Actinic Keratosis: Rationale and Management. Dermatology and Therapy, 4(1): 11-31. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4065271/.
  4. Marzuka, A.G. and Book, S.E. (2015). Basal Cell Carcinoma: Pathogenesis, Epidemiology, Clinical Features, Diagnosis, Histopathology, and Management. Yale Journal of Biology and Medicine, 88(2): 167-179. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4445438/.
  5. Evans, M.S., Madhunapantula, S.V., Robertson, G.P., and Drabick, J.J. (2013). Current and Future Trials of Targeted Therapies in Cutaneous Melanoma. Advances in Experimental Medicine and Biology, 779: 223–255. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3651924/.
  6. Evans, M.S., Madhunapantula, S.V., Robertson, G.P., and Drabick, J.J. (2013). Current and Future Trials of Targeted Therapies in Cutaneous Melanoma. Advances in Experimental Medicine and Biology, 779: 223–255. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3651924/.
  7. Evans, M.S., Madhunapantula, S.V., Robertson, G.P., and Drabick, J.J. (2013). Current and Future Trials of Targeted Therapies in Cutaneous Melanoma. Advances in Experimental Medicine and Biology, 779: 223–255. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3651924/.
  8. Evans, M.S., Madhunapantula, S.V., Robertson, G.P., and Drabick, J.J. (2013). Current and Future Trials of Targeted Therapies in Cutaneous Melanoma. Advances in Experimental Medicine and Biology, 779: 223–255. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3651924/.
  9. Latha, M.S., Martis, J., Shobha, V., Shinde, R.S., Bangera, S., Krishnankutty, B., Bellary, S., Varughese, S., Rao, P., and Kumar, B.R.N. (2013). Sunscreening Agents: A Review. The Journal of Clinical and Aesthetic Dermatology, 6(1): 16-26. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3543289/.
  10. Ley, R.D. and Reeve, V.E. (1997). Chemoprevention of ultraviolet radiation-induced skin cancer. Environmental Health Perspectives, 105(Suppl 4): 981–984. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1470017/.
  11. Ley, R.D. and Reeve, V.E. (1997). Chemoprevention of ultraviolet radiation-induced skin cancer. Environmental Health Perspectives, 105(Suppl 4): 981–984. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1470017/.
  12. McWhirter, J.E. and Hoffman-Goetz, L. (2015). Coverage of skin cancer and recreational tanning in North American magazines before and after the landmark 2006 International Agency for Research on Cancer report. BioMed Central Public Health, 15: 169. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4342877/.

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