About photosensitivity
People with photosensitivity have an immunological response to light, usually sunlight. They typically break out in a rash when exposed to sunlight; how much exposure it takes to cause a reaction varies from person to person. Several conditions, such as
erythropoietic protoporphyria and
polymorphous light eruption, share the common symptom of hypersensitivity to light—also typically sunlight.
People taking certain prescription drugs (sulfonamides, tetracycline, and thiazide diuretics) or herbs (St. John’s wort, for example) and those with systemic lupus erythematosus have increased susceptibility to adverse effects from sun exposure.
Product ratings for photosensitivity
★★★ Beta-carotene
★Adenosine monophosphate
★Fish oil
★Vitamin B3 (niacinamide)
★Vitamin B6
★Vitamin E
Key
★★★ Reliable and relatively consistent scientific data showing a substantial health benefit.
★★ Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
★ For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support and/or minimal health benefit.
What are the symptoms?
Symptoms may include a pink or red skin rash with blotchy blisters, scaly patches, or raised spots on areas directly exposed to the sun. The affected area may itch or burn, and the rash may last for several days. In some people, the reaction to sunlight gradually becomes less with subsequent exposures.
Medical options
Over-the-counter supplementation with beta-carotene may reduce the severity of reactions.
The prescription drug hydroxychloroquine (Plaquenil) might help to reduce the severity of reactions. Topical corticosteroids such as triamcinolone (Aristocort, Kenalog), betamethasone (Valisone, Diprosone), and fluocinonide (Lidex) are often prescribed to clear up the skin rash once it has appeared. In some cases, psoralens, such as trioxsalen (Trisoralen), plus ultraviolet therapy (PUVA) is administered over the course of several weeks to prevent photosensitivity.
Other treatment includes the avoidance of direct sunlight and the use of sunscreen. In addition, individuals should avoid medications and substances that are known to cause photosensitivity.
Dietary changes that may be helpful
One of the conditions that may trigger photosensitivity—porphyria cutanea tarda—has been linked to alcohol consumption.1 People with this form of porphyria should avoid alcohol. Some people have been reported to develop a photosensitivity reaction to the artificial sweetener, saccharin.2
Lifestyle changes that may be helpful
People with photosensitivity need to protect themselves from the sun by using sunscreen, wearing protective clothing (such as long-sleeved shirts), and avoiding excess exposure to the sun.
Vitamins that may be helpful
Years ago, researchers theorized that beta-carotene in skin might help protect against sensitivity to ultraviolet light from the sun. Large amounts of beta-carotene (up to 300,000 IU per day for at least several months) have allowed people with photosensitivity to stay out in the sun several times longer than they otherwise could tolerate.3 4 5 The protective effect appears to result from beta-carotene’s ability to protect against free-radical damage caused by sunlight.6
Adenosine monophosphate (AMP) is a substance made in the body that is also distributed as a supplement, although it is not widely available. According to one report, 90% of people with porphyria cutanea tarda responded well to 160 to 200 mg of AMP per day taken for at least one month.7 Complete alleviation of photosensitivity occurred in about half of the people who took AMP.
In a small preliminary trial, supplementation with fish oil (10 grams per day for three months) reduced photosensitivity in 90% of people suffering from polymorphous light eruptions.8
Less is known about the effects of supplementation with other antioxidants on photosensitivity. Research with vitamin E has been limited and has not yielded consistent results.9 10
Cases have been reported of people with photosensitivity who responded to vitamin B6 supplementation.11 12 Amounts of vitamin B6 used to successfully reduce reactions to sunlight have varied considerably. Some doctors suggest a trial of 100 to 200 mg per day for three months. People wishing to take more than 200 mg of vitamin B6 per day should do so only under medical supervision.
Niacinamide, a form of vitamin B3, can reduce the formation of a kynurenic acid—a substance that has been linked to photosensitivity. One trial studied the effects of niacinamide in people who had polymorphous light eruption.13 While taking one gram three times per day, most people remained free of problems, despite exposure to the sun. Because of the potential for adverse effects, people taking this much niacinamide should do so only under medical supervision.
References
1. Cripps DJ. Diet and alcohol effects on the manifestation of hepatic porphyrias. Fed Proc 1987;46:1894–900.
2. Gordon HH. Photosensitivity to saccharin. J Am Acad Dermatol 1983;8:565 [letter].
3. Mathews-Roth MM, Pathak MA, Fitzpatrick TB, et al. Beta-carotene as an oral photoprotective agent in erythropoietic protoporphyria. JAMA 1974;228:1004–8.
4. Nordlund JJ, Klaus SN, Mathews-Roth MM, Pathak MA. New therapy for polymorphous light eruption. Arch Dermatol 1973;108:710–2.
5. Mathews-Roth MM, Pathak MA, Fitzpatrick TB, et al. Beta-carotene as a photoprotective agent in erythropoietic protoporphyria. N Engl J Med 1970;282:1231–4.
6. Mathews-Roth MM. Photoprotection by carotenoids. Fed Proc 1987;46:1890–3 [review].
7. Gajdos A. AMP in porphyria cutanea tarda. Lancet 1974;I:163 [letter].
8. Rhodes LE, Durham BH, Fraser WD, Friedmann PS. Dietary fish oil reduces basal and ultraviolet B-generated PGE2 levels in skin and increases the threshold to provocation of polymorphic light eruption. J Invest Dermatol 1995;105:532–5.
9. Ayres S Jr, Mihan R. Porphyrea cutanea tarda: response to vitamin E. Cutis 1978;22:50.
10. Werninghaus K, Meydani M, Bhawan J, et al. Evaluation of the photoprotective effect of oral vitamin E supplementation. Arch Dermatol 1994;130:1257–61.
11. Kaufman G. Pyridoxine against amiodarone-induced photosensitivity. Lancet 1984;i:51–2 [letter].
12. Ross JB, Moss MA. Relief of the photosensitivity of erythropoietic protoporphyria by pyridoxine. J Am Acad Dermatol 1990;22:340–2.
13. Neumann R, Rappold E, Pohl-Markl H. Treatment of polymorphous light eruption with nicotinamide: a pilot study. Br J Dermatol 1986;115:77–80.
Source:
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