Shining a Light on the Role of Visible Light Photoprotection

Shining a Light on the Role of Visible Light Photoprotection in the Management of Hyperpigmentation Disorders and Photodermatoses

The role of visible light (VL) is often overlooked, yet emerging research suggests VL photoprotection is a valuable tool in managing hyperpigmentation and photodermatoses. Visible light, the portion of the electromagnetic spectrum visible to the human eye, spans a range of wavelengths from approximately 400 to 700 nanometers (1). While it is less energetic than UV, research indicates VL can contribute to hyperpigmentation, as well as trigger oxidative stress and inflammatory responses in the skin. Oxidative stress occurs when there is an imbalance between reactive oxygen species production and the body's ability to neutralize them(2). VL exposure has been linked to increased reactive oxygen species production in skin cells. These molecules can damage lipids, proteins, and DNA, leading to cellular dysfunction and inflammation(1). In individuals with photodermatoses, oxidative stress can aggravate symptoms and contribute to disease progression.

Hyperpigmentation is a complex skin condition affecting people of all skin types. It can be triggered by various factors, including UV radiation, hormones, inflammation, skin trauma, medications, and genetics. It occurs due to overproduction of melanin by the melanocytes and its distribution within the epidermis and dermis is a hallmark feature of this condition(2). Melanin absorbs both UV and VL, which can further exacerbate hyperpigmentation.

Photodermatoses encompass a range of skin conditions that manifest as abnormal reactions to sunlight. Common types include polymorphic light eruption (PMLE), actinic prurigo, and solar urticaria(1). These disorders can lead to symptoms such as itching, redness, swelling, and blisters upon sun exposure. Traditionally, UV radiation, particularly UVA and UVB rays, has been linked to the onset of photodermatoses. However, studies have shown that VL can contribute to the development of these conditions(3).

For a sunscreen to protect against VL, it must be visible on the skin. Mineral filters such as zinc oxide and titanium dioxide, are often used in the form of nanoparticles in sunscreens to minimize the chalky, white appearance(1). Therefore, they do not protect against VL. Tinted sunscreens use different formulations and concentrations of iron oxides and pigmentary titanium dioxide to provide protection against VL(2). Newer formulations are being developed that incorporate ingredients capable of absorbing or reflecting VL, thereby reducing its penetration into the skin. Many shades of tinted sunscreens are available by combining different amounts of iron oxides and pigmentary titanium dioxide to cater to all skin types(1). Therefore, tinted sunscreens are beneficial for patients with VL-induced photodermatoses and those with hyperpigmentation disorders.

Antioxidants are known for their ability to neutralize free radicals and reduce oxidative stress(2). Incorporating antioxidants like vitamin C and vitamin E into photoprotection and skincare routines can help mitigate the effects of VL-induced damage. Additionally, topical agents containing ingredients like ferulic acid and niacinamide have demonstrated the ability to mitigate VL-induced inflammation and reduce skin sensitivity(1).

Visible light photoprotection is an emerging area of research and skincare innovation that holds promise in managing and preventing photodermatoses and hyperpigmentation. As we continue to learn more about the damaging effects of VL on the skin, it's becoming increasingly important to incorporate strategies that offer comprehensive protection against both UV and VL(3). By encouraging broad-spectrum sunscreens, visible light filters, antioxidant-rich products and protective clothing, we can provide our patients with a comprehensive photoprotection plan for managing these difficult conditions.

1. Geisler AN, Austin E, Nguyen J, Hamzavi I, Jagdeo J, Lim HW. Visible light. Part II: Photoprotection against visible and ultraviolet light. J Am Acad Dermatol. 2021 May;84(5):1233-1244.

2. Passeron T, Lim HW, Goh CL, Kang HY, Ly F, et al. Photoprotection according to skin phototype and dermatoses: practical recommendations from an expert panel. J Eur Acad Dermatol Venereol. 2021;7:1460-1469.

3. Taylor S, Lim HW, Alexis A, Alexis AF, Armstrong AW, et al. Photoprotection for skin of all color: consensus and clinical guidance from an expert panel. J Am Acad Dermatol. 2022;86(3S):S1–S8.

Eileen Cheever MPAS, PA-C, resides with family in Massachusetts. She works at Clearview Dermatology in Leominster, Massachusetts. In her spare time, she enjoys cheering on her favorite Boston sports teams and exploring the outdoors with her family.