Photodermatitis is an abnormal skin reaction to sunlight, or more specifically to ultraviolet (UV) rays. It can be acute (sudden) or chronic (ongoing). Photodermatitis occurs when your immune system reacts to UV rays. You may develop a rash, blisters, or scaly patches. Exposure levels and reactions differ for every person.
Several factors can make your skin sensitive to UV rays, including having an inherited tendency to photosensitivity, taking certain medications, or being exposed to plants in the Apiaceal or Umbelliferae family, including weeds and edible plants, such as hogweed, cowbane, carrot, parsnip, dill, fennel, celery, and anise.
Signs of photodermatitis include:
Photodermatitis can have several causes, including:
In reaction to UV rays, certain chemicals and drugs can cause sunburn, an eczema-like reaction, or hives. The reaction may be related to an allergy, or it may be a direct toxic effect from the substance. Below are examples of substances or circumstances that may trigger one or the other type of reaction:
Direct toxic effect:
People who are most at risk include:
Your health care provider will perform a physical exam and take a detailed history of your exposure to chemicals, drugs (see What Causes It? section), and UV rays. Your provider may order blood and urine tests to detect any related diseases. Allergy tests may help identify substances that may trigger or worsen the condition.
These measures may help prevent photodermatitis:
For blisters or weepy eruptions, apply cool, wet dressings. With certain types of photodermatitis, doctors may use phototherapy (controlled exposure to light for treatment purposes) to desensitize the skin or to help control symptoms.
For extremely sun sensitive people, doctors may prescribe azathioprine to suppress the immune system. Short-term use of glucocorticoids may help control eruptions. For those who cannot be treated with phototherapy, doctors may prescribe hydroxychloroquine, thalidomide, beta-carotene, or nicotinamide (see Nutrition section).
Note: Thalidomide causes severe birth defects and should never be used by women who are pregnant or wish to become pregnant.
If you do not get enough of some nutrients, your skin can become sensitive to sunlight. Pellagra, for example, is caused by a niacin deficiency and leads to photosensitivity. Other nutrients, particularly antioxidants and flavonoids, may help protect skin against sun damage in healthy people. Antioxidants help protect skin from damage. Recent studies suggest that antioxidants, especially beta-carotene, may help lessen the symptoms of photodermatitis.
Some supplements and herbs may be beneficial for some people but cause side effects or undesired drug interactions in others. Always tell your health care providers about any supplement or complementary therapy you are using or considering using.
You may address nutritional deficiencies with the following supplements:
Herbs are generally available as standardized, dried extracts (pills, capsules, or tablets), teas, or tinctures/liquid extracts (alcohol extraction, unless otherwise noted). Mix liquid extracts with favorite beverage. Dose for teas is 1 to 2 heaping teaspoonfuls/cup water steeped for 10 to 15 minutes (roots need longer).
Herbs to avoid
Some herbs can cause photodermatitis, including:
Few studies have examined the effectiveness of specific homeopathic remedies. A professional homeopath, however, may recommend one or more of the following treatments for photodermatitis based on his or her knowledge and clinical experience. Before prescribing a remedy, homeopaths take into account a person's constitutional type, includes your physical, emotional, and intellectual makeup. An experienced homeopath assesses all of these factors when determining the most appropriate remedy for a particular individual.
Most photosensitivity reactions go away eventually and cause no permanent harm. However, symptoms can be serious when there is an underlying disease or when the exposure has been severe. Some photosensitivity reactions can continue for years after exposure ends.
Complications may include:
People who need steroids to treat photodermatitis must be monitored closely. In addition, anyone with a history of photodermatitis or photoreactivity should keep track of the frequency and duration of symptoms. This information can help determine appropriate treatment.
Afaq F, Malik A, Syed D, Maes D, Matsui M, Mukhtar H. Pomegranate fruit extract modulates UVB-mediated phosphorylation of mitogen activated protein kinases and activation of nuclear factor kappa B in normal human epidermal keratinocytes. Photochem Photobiol. 2005 Jan-Feb;81(1):38-45
Auerbach: Wilderness Medicine. 6th ed. St. Louis, MO: Elsevier Mosby; 2011.
Chen YA, Lee JY. Clinicopathologic study of solar dematitis, a pinpoint papular variant of polymorphous light eruption in Taiwan, and review of the literature. J Formos Med Assoc. 2013;112(3):125-30.
Goldman L, Bennett JC. Cecil Textbook of Medicine. 21st ed. Philadelphia, PA: W.B. Saunders; 2000:2295-2296.
Heinrich U, Neukam K, Tronnier H, Sies H, Stahl W. Long-term ingestion of high flavanol cocoa provides photoprotection against UV-induced erythema and improves skin condition in women. J Nutr. 2006 Jun;136(6):1565-9
Jindal N, Sharma NL, Mahajan VK, Shanker V, Tegta GR, Verma GK. Evaluation of photopatch test allergens for Indian patients of photodermatitis: preliminary results. Indian J Dermatol Venereol Leprol. 2011:77(2):148-55.
Katiyar SK, Afaq F, Perez A, Mukhtar H. Green tea polyphenol (-)-epigallocatechin-3-gallate treatment of human skin inhibits ultraviolet radiation-induced oxidative stress. Carcinogenesis. 2001 Feb;22(2):287-94.
Kerr H, Lim H. Photodermatoses in African Americans: A retrospectivce analysis of 135 patients over a 7-year period. J of the Amer Acad of Derm. 2007;57(4).
Morganti P. The photoprotective activity of nutraceuticals. Clin Dermatol. 2009;27(2):166-74.
Sasseville D. Clinical Patterns of Phytodermatitis. Dermatologic Clinics. 2009;27(3).
Stahl W, Heinrich U, Jungmann H, Sies H, Tronnier H. Carotenoids and carotenoids plus vitamin E protect against ultraviolet light-induced erythema in humans. Am J Clin Nutr. 2000;71(3):795-798.
Tierney LM, McPhee SJ, Papadakis MA. Current Medical Diagnosis and Treatment 2000. New York, NY: Lange Medical Books/McGraw-Hill; 2000:177-178.
Wu PA, James WD. Lavender. Dermatitis. 2011;22(6):344-7.
Reviewed By: Steven D. Ehrlich, NMD, Solutions Acupuncture, a private practice specializing in complementary and alternative medicine, Phoenix, AZ. Review provided by VeriMed Healthcare Network.
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- 2023 A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited.