What Causes Light Sensitivity?
* UVA light has been shown to have immunosuppression effects; a direct relationship has been established between these effects and skin carcinogensis in humans.
* Naturally (inherited) dark skin is less prone to melanoma, however artificially acquired dark skin (i.e., a tan) does not afford the same protection.
* The immune system is vulnerable to modification by environmental agents such as UV radiation, which appears to diminish its effectiveness by changing the activity and distribution of the cells responsible for triggering immune responses.
* Skin is more vulnerable to sun damage post surgery or while undergoing treatments such as chemical peels.
* Squamous cell carcinoma is the most common skin cancer in organ transplant patients.
* Sunscreen has been proven effective at preventing tumors of squamous cell cancer.
Photosensitivity can be genetic or acquired. It can be caused by environmental factors and/or may be the by-product of certain physiological conditions.
Environmentally, pollution has depleted the ozone layer. The deterioration of this natural atmospheric shield has left us all more vulnerable and led to a general increase in photosensitivity. In addition, we come into contact with more and more photosensitizers on a daily basis. Photosensitizers are substances that absorb UV from the sun or artificial light sources and induce adverse skin responses. These substances can reach us either topically or systemically. Photosensitizing ingredients, for example tars, psoralen compounds and halogenated salicylanilides, are routinely included in a host of everyday health and beauty products (perfumes, moisturizing creams, after-shave lotions, deodorant soaps), as well as in materials that are commonly used in certain industrial and agricultural sectors. Over 400 medications ranging from birth control pills to antibiotics to chemotherapy agents are know to cause photosensitive or photoallergic reactions.
Pigmentation is a major physiological factor in photosensitivity. Pigment provides protection against UV damage; an innate absence or acquired loss of pigmentation equates to greater photosensitivity. Fair skinned individuals (Skin types I or II) are naturally photosensitive, as are people who suffer from genetic conditions that preclude or impair pigment production. Pigment-related photosensitivity is acquired when skin destroys melanocytes and the ability to produce pigment.
A variety of diseases and disorders are aggravated by sun exposure and severely exacerbate photosensitivity. Organ transplant patients, patients undergoing Photodynamic Therapy (PTD), those who have had certain aesthetic procedures such as glycolic peels, microdermabrasion, or laser treatments are also photosensitive. Regardless of the cause, photosensitive individuals must practice daily, year-round sun protection. Both UVA and UVB are known to provoke phototoxic and photoallergic responses, which makes full spectrum protection an imperative. To maintain overall health, avoid skin damage and prevent skin cancer it is especially important for photosensitive people to following the recommendations:
* Apply a full spectrum sunscreen with a sun protection factor of at least 30 or higher. * Make sunscreen a normal part of the morning routine; Re-apply every 2 to 4 hours. * Wear protective clothing, long sleeved shirt and long pants when possible. * Regularly wear a wide brimmed hat and sunglasses with UV protection. * Limit outdoor activity between 10 AM and 4 PM.