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Photosensitivity (sun allergy) and vitamin D

Fact: Some people get reactions from having their skin exposed to the sun
Fact: Only some of the causes of photosensitivity are known
Fact: If you avoid the sun, you most likely vitamin D deficient, and should take supplements
Possibility: Taking vitamin D might decrease your photosensitivity - anecdotal reports

Photosensitive people have low levels of vitamin D – Aug 2014

New study highlights importance of vitamin D supplementation in patients sensitive to the sun Vitamin D Council

  • Currently, the United Kingdom Department of Health does not recommend oral vitamin D at any dose for healthy people.
  • It assumes people (in U.K.) are getting all the vitamin D they need from sun exposure.
  • Oral vitamin D is only recommended for people (in the U.K.) that are not able to go outside for a variety of reasons, and even then it is recommended that they only take 400 IU per day.

Photosensitives: 12.8 ng/mL; Controls 18.2 ng/mL,
Photosensitive during summer;

  • half had < 20 ng/mL
  • 10X use of sunscreen vs controls

Both groups reported using sunscreen on the face year round at the same rate.

Sunlight exposure behavior and vitamin D status in photosensitive patients: longitudinal comparative study with healthy individuals at UK latitude.
Br J Dermatol. 2014 Aug 11. doi: 10.1111/bjd.13325. [Epub ahead of print]
Rhodes LE1, Webb AR, Berry JL, Felton SJ, Marjanovic EJ, Wilkinson JD, Vail A, Kift R.

Low vitamin D status is prevalent in winter-time in populations at northerly latitudes. Photosensitive patients are advised to practice sun-avoidance, but their sunlight exposure levels, photoprotective measures and resulting vitamin D status are unknown.
Examine seasonal vitamin D status in photosensitive patients relative to healthy individuals and quantitatively assess behavioral and demographic contributors.
Longitudinal prospective cohort study (53.5°N) examining year-round 25-hydroxyvitamin D (25(OH)D) levels, sun-exposure behavior and oral vitamin D intake in photosensitive patients diagnosed at a photoinvestigation unit (n=53) compared with concurrently-assessed healthy adults (n=109).
Photosensitive patients achieved seasonal 25(OH)D variation, but insufficient (<20ng/ml; 50nmol/l) and even deficient (<10ng/ml; 25nmol/l) levels occurred at summer-peak in 47% and 9% patients respectively, rising to 73% and 32% at winter-trough. Adjusting for demographic factors, mean values were lower than for healthy volunteers by 18% (95%CI 4 to 29%) in summer (P=0.02), 25% (7 to 39%) in winter (P=0.01). Behavioral factors explained 25(OH)D differences between cohorts. Patients demonstrated lower weekend UVB-doses (P<0.001), smaller skin surface-area exposure (P=0.004) and greater sunscreen use (P<0.001), while average oral vitamin D intake was low in both groups (photosensitive: 2.94μg/day). Supplementation and summer surface-area exposure predicted summer-peak and winter-trough 25(OH)D; 1μg/day increment in vitamin D supplement raised summer and winter 25(OH)D by 5% (95%CI 3 to 7%) and 9% (5 to 12%) respectively (both P<0.001).
Photosensitive patients are, through their photoprotective measures, at high risk of year-round low vitamin D status. Guidance on oral measures should target this patient group and their physicians.
This article is protected by copyright. All rights reserved.
PMID: 25110159
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Sun’s Rays May Leave Mysterious Marks July 2011 NYT

Use original for hyperlinks)
Published: July 25, 2011 New York Times
For adults and children alike, summer is the season to take in the mystery of the outdoors, its unexpected pleasures and hidden thrills.

But summer has its share of unpleasant discoveries, too — as dermatologists know all too well. For this is also the season of the mystery rash. “This time of year, a lot of people come in with rashes and have no idea what happened,” said Dr. Deborah S. Sarnoff, a dermatologist in New York.

In truth, many of these rashes are not at all mysterious. Very often, Dr. Sarnoff and other dermatologists find, they result from a photosensitivity reaction, a combination of the sun’s UVA radiation and exposure to a drug, perfume or another substance.

Many commonly used drugs can cause such a reaction, including antibiotics like the tetracyclines (doxycycline is one), ciprofloxacin and the sulfa drugs (Bactrim, for example); the diuretic hydrochlorothiazide; and over-the-counter anti-inflammatory drugs, like ibuprofen and naproxen.

People with the photosensitive reactions “may have been on the drug for a long time, so they don’t put two and two together,” said Dr. Sarnoff, who is senior vice president of the Skin Cancer Foundation.

The full list of substances that can touch off a photosensitive reaction is very long and includes, ironically, sunscreens that contain benzophenones, the retinoids used to treat acne and sun-induced wrinkles, and fragrances like musk and coumarins.

The guilty substances change with the times, as compounds go in and out of fashion. But the problem never vanishes. New irritants frequently appear, keeping dermatologists on their toes and consumers mystified.

Most photosensitivity reactions result from exposure to UVA radiation, the so-called tanning rays that have been linked to premature aging of the skin and to melanoma, the most deadly form of skin cancer.

UVA radiation can pass through glass, so a reaction can occur after a car ride or sitting indoors near a window, further mystifying affected individuals. And though the sun is the most common source of UVA radiation, it is not the only source. This type of UV radiation is found in tanning booths and, in small amounts, is emitted by fluorescent bulbs.

Some people also react to the wavelengths that make up visible light.

Two Kinds of Photosensitivity
Photosensitivity — “a broad umbrella,” Dr. Sarnoff said — refers to two types of reactions. One, the kind that can happen to anyone, is called phototoxic, the effects of which resemble a very bad sunburn. It can occur the first time a person is exposed to a trigger.

The culprit, like many of the substances mentioned above, may be ingested or applied topically. It gets into the skin, where it is activated by UVA rays. Within a day, the sun-exposed skin turns very red.

While in theory anyone exposed to sufficient amounts of a phototoxic drug should react to UVA exposure, one’s susceptibility can be influenced by such factors as the amount of drug present in the skin, the color and thickness of the skin, and environmental conditions like humidity, temperature and wind.

Some phototoxic reactions depend on oxygen, and taking antioxidants like vitamin C and vitamin E orally may be protective, Dr. Sarnoff said. The second type, called photoallergic dermatitis, is much less common, affecting 1 to 2 percent of the population. It is what doctors call a delayed hypersensitivity reaction, more often resulting from application of topical substances, like perfumes, that can induce allergic reactions.

In past years, the sunscreen ingredient PABA caused photoallergic reactions in many people, and its use was discontinued.

In one 20-year study of 69 people with documented photoallergic dermatitis, doctors at New York University found that

  • antibiotics and ingredients in sunscreens each caused 23 percent of the reactions,
  • other medications 20 percent,
  • fragrances 13 percent and
  • substances from plants 11 percent.

As with poison ivy, for a photoallergy to develop a person must have exposure to the substance that resulted in no visible reaction, but alerted the immune system to recognize future exposures as something foreign.

Unlike phototoxic reactions, which require a rather strong exposure to the offending substance, a photoallergic response can result from relatively small amounts of the allergen. A photoallergic reaction doesn’t show up until two or three days later, so sufferers may not link it to sun exposure. The irritation can spread to areas that were not exposed to the sun. The rash may be itchy at first, then, like poison ivy, turn into watery blisters.

Some people with chronic illnesses are highly susceptible to photosensitivity reactions and must always protect themselves from UVA exposure. The conditions include

  • lupus,
  • pellagra and
  • porphyria.

People with a rare inherited disorder called xeroderma pigmentosum have extreme sensitivity to the sun and must avoid exposure at all times.

There is also a chronic form of sun sensitivity, most often seen in elderly men, that shows up as itchy red, inflamed bumps and scaly patches on sun-exposed skin, Dr. Sarnoff and co-authors wrote in The Skin Cancer Foundation Journal in 2008.

Testing and Treatment
Determining the cause of a photosensitivity reaction is likely to start with an inventory of the substances you are exposed to that are common culprits. Were you

  • on an antibiotic, or do you
  • take a thiazide diuretic or a
  • nonsteroidal anti-inflammatory drug?
  • Have you recently begun using a new scent or sunscreen?
  • Might you have been working with a particular plant or a pesticide?

To confirm sensitivity, you will have to undergo a photopatch test, similar to that used by allergists to test for allergic sensitivities. Several suspect substances are tested at once on the patient’s back, with two sites for each substance. One site is exposed to UVA, and its matching site is not. Then, some hours later, the doctor checks for a reaction.

“If there is a reaction at the UVA-exposed site but not at the protected one, there’s a high probability there will be a photosensitivity reaction in real life,” Dr. Sarnoff said.

The best way to deal with a photosensitivity reaction is to sidestep it. If at all possible, avoid exposure to the substance that caused it. If a medication was responsible, ask your doctor if you can switch to an alternative. If it resulted from a drug that you must take, you will have to avoid UVA exposure.

Dr. Sarnoff warned that sunscreens with high S.P.F. ratings that lack good UVA blockers are especially hazardous, because they allow you to stay in the sun without burning for far too long.

Several sunscreen ingredients are good UVA blockers. The best are micronized inorganic substances, titanium dioxide and zinc oxide, found in a number of products (check the labels). Avobenzone (Parsol 1789), Mexoryl and Helioplex (in Neutrogena products) are good UVA blockers, as well.

Specially designed sun-blocking garments are effective though expensive. The alternative is a regular garment made of tightly woven fabric, hardly an ideal solution on a hot summer day. Keep in mind that when an ordinary garment gets wet, it loses most of its ability to block sunlight.
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Mayo Clinic Sun Allergy

Sun allergy is a condition in which sunlight triggers a skin reaction.
For most people, sun allergy symptoms include an itchy red rash in areas that have been exposed to sunlight. A severe sun allergy may cause hives, blisters or other symptoms.
There are several types of sun allergy — including

  • polymorphic light eruption (PMLE),
  • actinic prurigo,
  • chronic actinic dermatitis (CAD) and
  • solar urticaria.

Details at Aetna

Extreme photosensitivity - EPP (Erythropoietic Protoporphyria) - very rare

Rare condition - about 1 in 100,000 people

Afamelanotide is peptide (created in Dec 2014 ?) which can the put under the skin which greatly reduces EPP for several months

Click here for details Oct 2015

http://www.porphyriafoundation.com/about-porphyria/types-of-porphyria/EPP Is one of many places describing EPP

Vitamin D deficiency in patients with erythropoietic protoporphyria Dec 2010
Severity of EPP is associated with the lack of vitamin D

Erythropoietic protoporphyria Wikipedia

  • First discovered 2008
  • Window films which block UV and visible light up to 450nm can provide relief from symptoms if applied to the patient's automobile and home windows.

See also VitaminDWiki

See also Web