Ultraviolet A Rays and skin conditions: The invisible threat
Ultraviolet A rays, a component of sunlight that reaches our skin daily, are powerful triggers for a range of skin conditions. While we enjoy the sunlight, it is crucial to be aware of the potential risks these rays bring with them. In this blog, we delve deeper into the skin conditions that can be provoked by UVA rays and discuss how we can effectively protect our skin, with a special focus on the natural UVA filter of Iconic Elements.
What about UVA rays in the Netherlands
In the Netherlands, as in other countries with a temperate climate, UVA rays are a constant aspect of sunlight exposure throughout the year. Due to the geographical location (far from the equator), characterized by the seasonal changes and frequently cloudy skies, the intensity and presence of UVB rays vary significantly. UVB rays are primarily powerful during the summer and at the times when the sun is strongest, between 10:00 and 16:00 hours. Outside these times, and especially in the autumn, winter, and spring, when the sun is lower, the UVB radiation is significantly weaker.
On the other hand, UVA rays remain fairly consistent in intensity throughout the year and are not so much influenced by the time of day or season. They are capable of penetrating through clouds and glass, which means you can also be exposed to UVA radiation on cloudy days or indoors (such as in a car or behind a window).
- Consistent exposure: Given that the presence of UVA rays is fairly constant throughout the year, their cumulative effect on the skin is significant, even in a country with a climate like the Netherlands.
- Deep penetration: UVA rays penetrate deeper into the skin than UVB rays, which means they can potentially cause more damage to the deeper layers of the skin.
- Protection all year round: The fact that UVA rays always pose a risk, emphasises the need for daily sun protection, even during the less sunny months. This is particularly important in the Netherlands, where the tendency to think about sunscreen outside of the summer season may be less.
Do you want to know more about the differences between UVA, UVB and SPF
Ultraviolet A Rays and Skin Conditions
Premature Skin Aging
When UVA rays penetrate the skin, they reach the deeper layers where collagen and elastine are located. Collagen and elastine are proteins that give our skin firmness and elasticity. You can think of them as the supporting frame that ensures our skin remains tight and resilient.
Unfortunately, UVA rays can damage this “frame”. They cause changes in the structure of collagen and elastin, causing these proteins to break down and the skin to lose its firmness. This process is accelerated by enzymes called matrix metalloproteinases (MMPs), which become more active under the influence of UVA radiation and contribute to the breakdown of collagen.
Sun Allergy
Sun allergies, caused or exacerbated by UVA rays, include various skin conditions that vary in symptoms and severity. Below, some of the most common forms of sun allergies are described, along with an explanation of the biochemical processes that cause or exacerbate these conditions.
Polymorphic Light Eruption (PMLE)
PMLE is the most common form of sun allergy, characterized by an itchy or burning rash that appears several hours to days after exposure to the sun. The rash occurs primarily on parts of the skin that are not accustomed to sunlight.
The exact cause of PMLE is not fully understood, but research suggests that UVA radiation (75-90% of cases) causes damage in skin cells, leading to the formation of abnormal reactions that are seen by the immune system as foreign. This triggers an allergic reaction, in which T-cells are activated and inflammation substances are released, resulting in the characteristic symptoms of PMLE such as skin rash and itching.
Actinic Prurigo
Actinic prurigo is a more severe form of sun allergy that leads to chronic skin rash and itching. It is more common in Native Americans and usually begins in childhood.
Just like PMLE, actinic prurigo is believed to be caused by an immune-mediated response to damage to skin cells induced by UVA and also UVB. This depends on genetic predisposition. In some, UVA causes these complaints, others only UVB or UVA and UVB. The condition is characterized by an increased expression of co-stimulatory molecules and adhesion molecules, which promote enhanced T-cell activation and a subsequent inflammatory response. This inflammatory response is aggravated by cytokines and chemokines which stimulate the migration of immune cells to the skin.
Simply put: Imagine your body has an advanced security system that activates extra protection when there is danger. With certain conditions, your body sends signals (co-stimulatory and adhesion molecules) that activate a team of special agents (T-cells). These agents start an inflammatory response to fight off intruders. At the same time, they call for reinforcements (by cytokines and chemokines) that bring more security to the skin. This entire process is meant to protect you, but sometimes the response can be too strong, leading to skin problems.
Photoallergic Contact Dermatitis
This form of dermatitis occurs when certain substances on the skin (such as perfumes, sunscreens, or medicines) react with UVA radiation, leading to an allergic reaction.
UVA rays activate chemical substances on the skin, transforming them into allergens. These allergens are absorbed and presented to T cells by Langerhans cells (immune cells in the skin), initiating a specific immune response. This process involves the release of inflammatory mediators that cause dermatitis.
So: imagine that some chemicals on your skin turn into substances your body is not happy with, the so-called allergens. Special cells in your skin, the Langerhans cells, pick up these allergens and show them to other cells (T-cells) that help protect your body. This triggers a chain reaction in which substances are released that cause inflammation, and this leads to a skin reaction that we call dermatitis.
Solar Urticaria
Solar urticaria, also known as sun allergy, is a rare condition in which exposure to sunlight quickly causes hives or welts on the sun-exposed skin. These skin reactions usually appear within a few minutes after exposure and can range from mild to severe.
In solar urticaria, UVA radiation, or sometimes even visible light, can activate the release of histamine and other vasoactive substances from mast cells. These substances can indeed cause vasodilation and increased vascular permeability, resulting in the formation of hives. However, it is not only UVA radiation that can cause this; some people with solar urticaria also respond to UVB or visible light. A longitudinal study of 27 patients with solar urticaria revealed that for 44% of the patients the action spectrum was UVB, for 70% it was UVA, for 89% it was UVA-1, for 37% green light, and for 22% red light.
So for the three sun allergies, the trigger by UVA plays a major role.
Pigmentation Spots
UVA rays penetrate deeply into the skin and reach the dermis, where they influence melanocytes, the cells responsible for the production of the pigment melanin. UVA radiation causes oxidative stress and DNA damage in these cells, leading to increased production of melanin as a protective mechanism. This increased production of melanin results in the accumulation of pigment in the upper skin layers, resulting in the appearance of dark spots or hyperpigmentation, especially on areas often exposed to the sun, such as the face and hands. This process is further enhanced by the activation of specific signal transduction pathways involved in the cellular response to UV radiation, such as the MAPK/ERK pathway that stimulates melanogenesis, or pigment production.
Skin Cancer
UVA radiation is notorious for its ability to penetrate deep into the skin, reaching the dermis, which goes beyond the more superficial epidermis. This type of radiation can cause significant DNA damage, both indirectly through the formation of free radicals and directly. Free radicals can cause oxidative stress and damage important cellular components such as lipids, proteins, and DNA. Direct DNA damage from UVA includes the formation of cyclobutane pyrimidine dimers (CPDs) and pyrimidine-pyrimidone at photoproducts. These harmful photoproducts can disrupt the stability of the DNA in skin cells, which can lead to mutations and the development of skin cancers such as melanoma and squamous cell carcinoma.
Unfortunately, these DNA damages are not always efficiently repaired by the cellular repair mechanisms, which can result in the accumulation of genetic damage and ultimately oncogenesis, or cancer formation. The human body has repair processes such as nucleotide excision repair to fix such damage. However, when the damage is overwhelming or the repair mechanism inadequate, this can contribute to the development of cancer. This underscores the importance of adequate protection against UVA radiation to keep the skin healthy and reduce the risk of skin cancer.
Iconic Elements and your skin
At Iconic Elements, we understand the importance of safe and effective sun protection. Our natural UVA filter has been developed to provide maximum protection, while also taking into account the health of your skin and the environment. By using our products, you can enjoy the sun while protecting your skin from the aforementioned conditions and contributing to a healthy, youthful appearance.
Protecting your skin from UVA rays is more than a daily routine; it’s an investment in your skin health and wellbeing. Choose Iconic Elements and take a crucial step in preventing skin conditions caused by sunlight, while enjoying natural beauty.
Disclaimer
For the three types of sun allergies, UVA radiation plays an important role as a trigger, in addition to to a lesser extent UVB radiation and visible light. Before taking precautions, it is advisable to undergo light tests to determine which of the three triggers cause a reaction in you. Because only protection against UVA radiation may not always be sufficient, it is important to have this properly tested.
