Photodermatitis, sometimes referred to as sun poisoning or photoallergy, is a form of allergic dermatitis in which the allergen must be activated by light to sensitize the allergic response, and to cause a rash or other systemic effects on subsequent exposure. The second and subsequent exposures produce photoallergic skin conditions which are often . It is distinct from sunburn.
Some variants are caused by topical exposure, while others are caused by medications, and still others are caused by medical conditions which generate the allergen precursors in the body.
Signs and symptoms
Photodermatitis may result in swelling, difficulty breathing, a burning sensation, a red itchy
rash sometimes resembling small
blisters, and peeling of the skin.
Nausea may also occur. There may also be blotches where the itching may persist for long periods of time. In these areas an unsightly orange to brown tint may form, usually near or on the face.
Causes
Many medications and conditions can cause sun sensitivity, including:
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Sulfa used in some drugs, among them some antibiotics, diuretics, COX-2 inhibitors, and diabetes drugs.
[ Sulfa Allergy Symptoms and Risks]
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, , photo-active dyes (eosin, acridine orange).
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Musk ambrette, methylcoumarin, lemon oil (may be present in fragrances).
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PABA (found in sunscreens).
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Oxybenzone (UVA and UVB chemical blocker also in sunscreens).
[Rodriguez E, Valbuena MC, Rey M, Porras de Quintana L. 2006. Causal agents of photoallergic contact dermatitis diagnosed in the national institute of dermatology of Colombia. Photodermatol Photoimmunol Photomed 22(4): 189-192.]
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Salicylanilide (found in industrial cleaners).
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St John's wort.
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Hexachlorophene (found in some prescription antibacterial soaps).
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Tetracycline antibiotics (e.g., tetracycline, doxycycline, minocycline).
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Benzoyl peroxide.
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(e.g., isotretinoin).
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Some (e.g., ibuprofen, naproxen sodium).
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Fluoroquinolone antibiotic: Sparfloxacin in 2% of cases.
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Amiodarone, used to treat atrial fibrillation.
Non-medication conditions that can cause it include:
Photodermatitis can also be caused by plants such as Ammi majus, parsnip, giant hogweed ( Heracleum mantegazzianum), common rue ( Ruta graveolens), and Dictamnus, a genus of angiosperms in the family Rutaceae with a single species Dictamnus albus, commonly called othe burning bush. Photodermatitis caused by plants is called phytophotodermatitis.
Prevention
Prevention includes avoiding exposure to chemicals that can trigger the reaction, such as by wearing gloves, or avoiding sunlight or wearing
sunscreen[ Archived AAD - The Sun and Your Skin, "Allergic Reactions" section] preferably with at least factor 30 and with a high UVA protection level on the affected area. And by addressing any risk factors, such as those listed above.
See also
External links
