Protecting Our Largest Organ: How Climate Change Impacts Skin Health

Climate change is marked by rapid and significant alterations in Earth’s climate patterns, primarily driven by human activities that release greenhouse gases into the atmosphere through fossil fuel burning, deforestation, and industrial processes. These gases trap heat, causing a planet-wide warming, disrupting weather patterns, and upsetting the balance of nature. The consequences extend beyond environmental concerns, profoundly impacting human health. The World Health Organization (WHO) identified population and climate change as a major environmental threat to global health¹.

In 2022, the American Medical Association declared climate change a public health crisis that jeopardizes the wellbeing of all people². The increased frequency and severity of extreme weather events, like heatwaves, storms, and floods, pose immediate risks to human lives, leading to injuries, displacement, disease exacerbations, and the introduction of new diseases.

These adverse impacts are already occurring and are projected to worsen if little is done to slow the progression of climate change. The influences on health are wide-ranging and interdisciplinary, with every medical specialty witnessing or set to witness the detrimental effects of global climate change on patients and their wellbeing, including dermatology.

The skin, being the largest organ in the body, serves as the primary defense against external insults such as irritants, allergens, and pathogens. Intricately linked to the surrounding environment, the skin’s health and susceptibility to diseases are impacted by climate change. As global temperatures rise and weather patterns become more unpredictable, individuals are experiencing a myriad of cutaneous diseases that are both alarming and challenging for dermatologists to address.

Global warming and air pollution can exacerbate inflammatory dermatoses like acne, psoriasis, and atopic dermatitis^3,4. These diseases are exacerbated by the intensifying heat and higher humidity levels. Atopic dermatitis (AD) is a chronic, inflammatory dermatosis characterized by pruritic, scaly patches and plaques. The etiology of AD is multifactorial, involving genetic predisposition, immune dysregulation, and environmental factors. Both extremely cold and hot, humid weather are postulated to increase AD flares⁵. Additionally, some evidence suggests that extreme temperatures, whether low or high, may impact the pruritus associated with AD through the increase activation of sensory nerves fibers located on the skin in response to noxious stimulation and temperature changes^3,5.

Furthermore, increases in wildfires release irritative pollutants into the atmosphere, heightening the risk of AD flares for both pediatric and geriatric populations. A 2022 study identified geriatric populations as particularly susceptible to AD exacerbations due to exposure to air pollution from California wildfires⁶. Additionally, climate change contributes to ecosystem shifts, exposing individuals to new allergens and irritants that may result in increased allergic reactions like contact dermatitis and hives³.

The release of greenhouse gases into the atmosphere ultimately depletes the stratospheric ozone layer. This depletion weakens the ozone layer’s ability to effectively filter out ultraviolet radiation (UVR), leading to elevated UVR levels reaching the Earth’s surface and an increased risk of photocarcinogenesis. Exposure to UVR is a known risk factor for developing basal cell carcinoma, squamous cell carcinoma, and melanoma—three of the most prevalent forms of skin malignancies.

Studies suggest that for every 1% reduction in the ozone layer’s thickness, the incidence of melanoma is predicted to rise by 1 to 2%, while the risk of squamous cell carcinoma and basal cell carcinoma are predicted to increase by 3-4.6% and 1.7-2.7%, respectively⁷. In addition to ozone layer depletion, global warming is closely associated with behaviors that incentivize increased outdoor activities, resulting in extended sun exposure for both children and adults. Individuals employed in outdoor professions, such as agricultural and construction workers, are particularly vulnerable to increased occupational exposure to UVR and extreme heat without proper sun protection.

The health crises resulting from climate change exacerbate local and global health inequities, particularly in low-income countries in sub-Saharan Africa, where socioeconomic conditions strongly correlate with climatic conditions.

Predictions suggest that the loss of healthy life years due to climate change in sub-Saharan Africa could be up to 500 times greater than in Europe⁸.

In Malawi, individuals with albinism face a severe health crisis as skin cancer becomes one of leading cause of death. Albinism, affecting one in 150 Malawians, increases susceptibility to skin cancer, exacerbated by economic vulnerabilities that necessitate outdoor labor⁹. Climate change compounds the issue, with extreme heatwaves linked to higher rates of skin cancer.

The World Bank estimates that by 2050, over 143 million new ‘climate migrants’ in Sub-Saharan Africa, South Asia, and Latin America will be forced into migration due to extreme weather events and environmental degradation^8,10. Climate change-induced displacement has profound implications for cutaneous infectious diseases. Overcrowded refugee camps and temporary shelters can facilitate the transmission of conditions like scabies, fungal infections, and lice^8,10,11. The disruption of healthcare infrastructure in the wake of displacement poses challenges in timely diagnosis and treatment, exacerbating the burden of dermatologic infections within vulnerable communities.

Climate change has a multifaceted impact on dermatologic conditions. Rising temperatures and increased UV radiation contribute to higher skin cancer rates, especially among vulnerable populations. Environmental shifts also lead to altered patterns of infectious diseases affecting the skin, such as vector-borne illnesses. Changing climate conditions worsen existing economic and societal challenges, including shortages of sun protection resources and limited access to healthcare services in low-resourced communities and countries. Dermatologists must actively advocate for policies that mitigate the effects of climate change, recognizing their pivotal role in promoting the wellbeing of their patients and fostering a sustainable, healthier future.

References:

1. Climate change. World Health Organization. October 12, 2023. Accessed 2023. https://www.who.int/news-room/fact-sheets/detail/climate-change-and-health.
2. AMA adopts new policy declaring climate change a public health crisis. American Medical Association. June 13, 2022. Accessed 2023. https://www.ama-assn.org/press-center/press-releases/ama-adopts-new-policy-declaring-climate-change-public-health-crisis.
3. Anderson A, Bruce F, Soyer HP, Williams C, Saunderson RB. The impact of climate change on skin health. Med J Aust. 2023;218(9):388-390. doi:10.5694/mja2.51931
4. Silva GS, Rosenbach M. Climate change and dermatology: An introduction to a special topic, for this special issue. Int J Womens Dermatol. 2021;7(1):3-7. doi:10.1016/j.ijwd.2020.08.002
5. Nguyen GH, Andersen LK, Davis MDP. Climate change and atopic dermatitis: is there a link?. Int J Dermatol. 2019;58(3):279-282. doi:10.1111/ijd.14016
6. Fadadu RP, Green M, Jewell NP, Grimes B, Vargo J, Wei ML. Association of Exposure to Wildfire Air Pollution With Exacerbations of Atopic Dermatitis and Itch Among Older Adults. JAMA Netw Open. 2022;5(10):e2238594. Published 2022 Oct 3. doi:10.1001/jamanetworkopen.2022.38594
7. Lin MJ, Torbeck RL, Dubin DP, Lin CE, Khorasani H. Climate change and skin cancer. J Eur Acad Dermatol Venereol. 2019;33(9):e324-e325. doi:10.1111/jdv.15622
8. Coates SJ, Enbiale W, Davis MDP, Andersen LK. The effects of climate change on human health in Africa, a dermatologic perspective: a report from the International Society of Dermatology Climate Change Committee. Int J Dermatol. 2020;59(3):265-278. doi:10.1111/ijd.14759
9. Mhango HK. Climate change posing existential threat to Malawians with albinism. The National. July 3, 2023. Accessed 2023. https://www.thenationalnews.com/world/africa/2023/07/03/climate-change-posing-existential-threat-to-malawians-with-albinism/
10. Choi SH, Beer J, Charrow A. Climate change and the displaced person: how vectors and climate are changing the landscape of infectious diseases among displaced and migrant populations. Int J Dermatol. 2023;62(5):681-684. doi:10.1111/ijd.16636
11. Kwak R, Kamal K, Charrow A, Khalifian S. Mass migration and climate change: Dermatologic manifestations. Int J Womens Dermatol. 2020;7(1):98-106. Published 2020 Aug 20. doi:10.1016/j.ijwd.2020.07.014