Tuesday, 20 April 2021 13:44

Photosensitivity Facets: The Science of the Skin’s Reactions to the Sun

Written by   Annette Hanson

Aestheticians warn clients about the dangers and negative effects of prolonged sun exposureencouraging the use of sunscreen daily, wide brimmed hats, and sunglasses whenever they are outdoors for a long period of time, especially during peak hours. The sun’s ultraviolet light damages the epidermis by reducing its elasticity, which leads to premature aging and in more severe cases, skin cancer. The epidermis contains melanocytes, and these cells producemelanin. Once the skin is exposed to ultraviolet radiation, melanin production increases and is responsible for the tan effect.However, this is actually the skin trying to protect itself from further damage.Melanin contributes to the skin’s color; it is also the same pigment that colors every individual’s hair and eyes.Nevertheless, there are people who are allergic to the sun.It is truly critical to understand photosensitivity, as well as the necessary steps to take in order to protect the skin’s health. 



Most clients’ skin will burn if there is enough exposure to ultraviolet radiation.However, some will burneasily or develop exaggerated reactions to sunlight.This condition is called photosensitivity.

If one develops photosensitivity, even limited sun exposure can put them at risk for lasting skin damage and skin cancer.Many can develop dry, red, or itchy inflammation on skin (sometimes including painful blisters and sores) that have been exposed to the sun’s ultraviolet rays.The skin around the chest and arms becomes red and blotchy, and it can take up to a week for the symptoms to clear. This condition is most common in White women with fair skin.In more severe cases, people also report fever, fatigue, and joint pain. A more dramatic sun allergy produces large hives on sun exposed skin. This rare condition is called solar urticaria. If a large enough area of skin has been exposed and develops a reaction, one can go into anaphylactic shock. This occurs when sunlight triggers an abnormal immune response that causes some to have a reaction to the sun.Researchers discovered that Langerhans, a type of immune cellappear to play an important role in photosensitivity.Doctor are looking for a better understanding of the cellular mechanisms involved in photosensitivity to lead to better treatment options.There are two types of sensitivities to be distinguished, including phototoxicity and photoallergy.



In phototoxicity, all reactionsonly appear on areas of skin that have been exposed to the sun. They usually develop within hours after sun exposure.

Some may report pain and develop redness withinflammation alongside discoloration ofskin. Their symptoms resemble a sunburn; however,it differs because individuals report the symptoms after taking certain medications.

Some common types of phototoxic drugs include:

  • Tetracyclines: antibiotics used to treat urinary tract and respiratory infections
  • Doxycycline: a common acne medication
  • Antihistamines like Benadryl 
  • Nonsteroidal anti-inflammatory drugs (NSAIDS) like aspirin and ibuprofen
  • Chemotherapy drugs and cancer drugs 
  • Cardiac drugs
  • Statins: cholesterol lowering drugs like Lipitor and Rosuvastatin (Crestor)
  • Diuretics (hydrochlorothiazide and Lasix): water pills, used mainly to treat high blood pressure by helping the body get rid of salt and water
  • Diabetic drugs (glyburide): used to lower blood sugar levels
  • Psychiatric drugs: antidepressants like Zoloft, Paxil, and Trazodone 
  • Anti-fungal drugs (fluconazole and ketoconazole): used to treat skin infections like ringworm, athletes’ foot, jock itch, and nail infections

It should be noted that not everyone taking any of these drugs will develop reactions. Certain individuals have more susceptibility to these medications than others. 


Ultraviolet rays interact with the ingredients in these medications; it is not just an oral reaction.Sometimes products applied directly to the skin can become activated by exposure to sunlight.For example, topical retinol can cause the skin to become more sensitive to ultraviolet rays.The body’s immune system recognizes changes caused by sun exposure as a foreign threat. The body produces antibodies and attacks, causing a reaction, and enhances the risk of sunburns and photo damage to the skin.It is an aesthetician’s job to research their client’s medications and the side effects either through written or verbal consultation



With photoallergic reactionsthere may be redness, scaling, itching, and sometimes blisters and spots that look like hives.It generally presents itself like a rash and looks similar toa sunburn or eczema.Blisters may also appear and the area is often painful and hot.This type of reaction can be caused by certain chemical compounds found in products like perfumes, lotionsand even some sunscreens. This happens after the person has used the product and has been exposed to sunlight. The sunlight is what makes the substance capable of triggering the photoallergy.Photoallergic reactions can also affect areas of skin that have not been exposed to the sun. They usually develop 24 to 72 hours after sun exposure.Having other skin issues like dermatitis and rosacea also increases the riskof an individual having a sun allergy. 



Up to 60 % of people who suffer from certain autoimmune diseases also suffer from photosensitivity. Diseases like lupus, where the body attacks its own cells and organs; multiple sclerosis (MS), affecting the brain and spinal cordand sclerodermachronic hardening and tightening of the skin and connective tissuesare just a few of them. 

To diagnose a sun allergy, doctors perform an ultraviolet light testing to see how skin reacts to different wavelengths of ultraviolet light from a special lamp.They may also conduct a photo patch test to see if the sun allergy is caused by a topical product before exposing the area to the sun. Common triggers are applied to the skin and, after a day, the area receives a dose of ultraviolet rays from a sun lamp to see if there is a reaction in the light-exposed area. Finally, sometimes blood tests are taken to rule out autoimmune diseases that can cause some to react to the sun. 

 Some fruits and vegetables may cause sun sensitivity if they come into contact with the skinPhytophotodermatitis is a condition caused by a toxic reaction when certain plant chemicals put on the skin are exposed to sunlight (phyto means plantand photo means light).Lime juice contains the chemical compound psoralen.1Other plants such as celery root, parsley parsnips, mango peel, and figs also contain psoralen.

Phytophotodermatitis can closely resemble contact dermatitis or a chemical burn. This condition is also colloquially called Bartender’s dermatitis – for when a bartender at an outdoor function in the summer sun gets lime juice on their hands, andthey suffer a lime juice burn while preparing cocktails.



A photosensitive ingredient is sensitive to light. It oxidizes and deteriorates when it meets the sun.The product’s color, texture, or fragrance could change, and it may lose some of its properties. Vitamin C is photosensitive and neutralizes free radicals and prevents photoaging.There have been experiments with vitamin C serums where the bottle is left in the sunlight and the clear color of the liquid will change to an orange shade.Both alpha hydroxy acid(glycolic, lactic, citric, malic, and mandelic) and beta hydroxy acid (salicylic) are neither photosensitive nor photosensitizing, but clients should avoid them before going out in the sun.These acids work to exfoliate the dead skin cells on the epidermis.Using products with alpha hydroxy acids or beta hydroxy acids and then going in the sun will make the skin much more vulnerable to ultraviolet rays. This means that if one uses acids without properly protecting the skin, they will burn more easily. The same thing occurs with retinolas well.



Chemical peels and laser treatments should be avoided for clients with sun allergies because of increased sun sensitivity. Chemical peels promote the growth of a new, healthy top layer of skin to improve issues like hyperpigmentation, fine lines and wrinkles, and uneven texture.Direct sun exposure and excessive heat should be avoided.If a clientlight sensitivity is drug induced, there are many common medications that can cause the skin to be extremely sensitive to the light of the laser when they are taking the medication. The skin could react negatively if the client is taking a photosensitive medication and having laser hair removal treatments.When a client is planning to start laser hair removal, it is important to let the practitioner know every single drug they are takingduring the consultation.All medications have side effects. If taking a medication that has a side effect of light sensitivity,clients should not have laser hair removal treatments.



Using a broad-spectrumsunscreen can reduce the risk of sun sensitivities.It is also important to remind clients to stay out of direct sunlight between the hours of 10 a.m. to fourp.m. when ultraviolet rays are especially intense.This can occur at higher altitudes and around snow or water.If one is going to be outdoors for longer than a few minutes (even on cloudy days),use a sunscreen with a sun protection factor of at least 30 that blocks both UVA and UVB rays. It should be applied liberally, especially on the face, neck, forehead, and ears about 20-minutes before going outdoors. Even water-resistant sunscreens should be reapplied about every 80-minutes after swimming or strenuous activity.

Sunbathers often assume they get twice as much protection from SPF 100 sunscreen overSPF 50however, the extra protection is negligible.Properly applied SPF 50 sunscreens block98of UVB rays; SPF 100 blocks 99%.When used correctly, sunscreen with SPF values between 30 and 50 offers adequate sunburn protection, even for those who are most sensitive to sunburn. 

Those who are photosensitive are told to gradually increase the amount of time they spend outdoors sotheir skin cells have time to adapt to sunlight.It is also extremely important to use the right sunscreen.Ultraviolet rays are made up of UVA and UVB rays, but UVA rays trigger sun-induced skin disorders. Retail sunscreen that contains ingredients like titanium dioxide or zinc oxide, which block both types of rays.Even people with dark skin benefit from this type of sunscreen with an SPF of at least 30. Remember that sunscreen and sun avoidance decrease the incidence of cancer and unevenness of pigmentation in people of all skin colors. 



Those who experience a reaction to the sun can suffer for days. In many cases, their skin is raw, irritated, and sensitive to touch.They are told to use cool, wet compresses on aggravated areas to avoid scratching.Cool or lukewarm baths and gentle, fragrance-free cleansers are recommended. Oatmeal baths and calamine lotion are also encouraged to relieve symptoms for people who have serious reactions.Immediately after bathing, recommend clients to use a gentle, hypoallergenic moisturizing cream to soothe skin. Treatment can also include using a steroid cream like hydrocortisone or taking an oral antihistamine like Benadryl to deal with the allergic response in the body.Vinegar soaks (one teaspoon of white vinegar to one cup of cold water) every 20 minutes, every three to six hours are also recommended.Dip cotton squares in the vinegar solution and apply directly on affected areas.Ice may also be applied directly on top of the vinegar solution.Doctors also encourage clients who suffer from photosensitivity to gradually increase how their body reacts to sunlight and to wear polarized sunglasses to cut down on the glare when outside. 



The damaging effects of ultraviolet radiation do not happen overnight.It is an accumulation of heavy sun exposure over the years that is responsible for the risk of developing skin cancer.The risks increase with two main factors: the amount of time spent under the sun and the intensity of radiation (the time of day, the location, and the reflection from surfaces).For those who are photosensitive, even on short-term basis, occasional sun exposure puts them at risk.Childhood sun exposure may also play an important part in the development of these cancers later in adult life. 

If a client is photosensitive,they may be at risk for lasting skin damage and skin cancer from even limited exposure to ultraviolet radiation.Constant exposure to sunlight causes an increased chance of developing one of the forms of skin cancer, like basal cell carcinomaand cutaneous malignant melanoma. High levels of chronic exposure to ultraviolet rays are more often associated with squamous cell tumors.


Basal Cell Cancer

Basal cell cancer is usually found in areas of the skin exposed to sunlight.This type of skin cancer appears as a raised, hard, and red wound often found on the forehead, eyelids, cheeks, nose, and lips.Basal cell cancer usually does notspreadand most cases are easily treated and cured.


Squamous Cell Cancer 

Squamous cell cancer occurs most frequently on the skin exposed to sunlight over longer periods of time. This type of skin cancer tends to develop where maximum exposure to radiation occurs, like the forehead, cheeks, nose, lips, and ears. It also usually develops in areas where the skin has already been damaged by the sun, like in areas with hyperpigmentation and sunspots. The blemishes develop into rough, scaly patches with small areas of open wounds that do notheal. If caught in timethis type of cancer can be removed with a good chance of recovery.


Malignant Melanoma 

Malignant melanoma is the most serious of the skin cancers. It is the rarest form and often shows itself as a mole or pigment spot that begins to bleed, grow, or change in color, shape, or texture. It usually spreads if not treated in the early stage.Brief intense exposure to strong sunlight appears to increase the risk of malignant melanoma in people who cannot handle strong sunlight (photosensitive). If caught early, malignant melanoma can be treated and cured. However, if treatment is delayed, this type of cancer is often fatal.



Every year, the clocks are turned forward to signal a new season of longer days and sunlight. This brings more picnics in the park, outdoor sports, and days lounging at the beach.However, those who suffer from sun sensitivity actually dread this time of year.For them it is a stressful time that causes major embarrassment. The frequency and severity of a sun allergy varies from person to person.Clients should see a doctor if unusual skin reactions are spotted after spending time in the sun, especially if symptoms persist. 



Annette Hanson 2019Annette Hanson is the founder of Atelier Esthétique Institute of Esthetics in Manhattan, a New York state licensing, NACCAS-accredited skin care school, post-graduate facility, and the first United States aesthetics college to be recognized by London’s International Therapy Examination Council (ITEC). Her professional experience spans more than 30 years as a Paris-trained aesthetician, waxing specialist, body therapist, salon manager, and spa consultant. She was instrumental in the development of the 600-hour curriculum for the New York state aesthetics license, as well as the written and practical exam. She was inducted into the Aesthetics International Association (A.I.A.) industry legends in August 2009 by DERMASCOPE Magazine.  





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