Sunlight Vs UVA Treatment for Psoriasis
Sunlight has a beneficial effect on psoriasis, a chronic, inflammatory, non-contagious skin disease, says dermatologist Dr. Richard Langley. The ultraviolet B (UVB) rays are the burning ones while the ultraviolet A (UVA) rays have little effect on their own.
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Types
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Natural sunlight contains three types of UV, says Langley. UVC (110-290 nanometers) is blocked by the earth's ozone layer. UVB (290-320nm) is highly effective in treating psoriasis and causes sunburn. UVA ( 320-400nm) is less effective.
Phototherapy
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Most artificial light therapy, phototherapy, is done with UVB light, as UVA is only marginally effective on its own, says the National Psoriasis Foundation (NPF).
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PUVA
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Physicians boost UVA's effectiveness by adding the light-sensitizing drug psoralen in a treatment known as PUVA (psoralen and UVA). This slows skin cell growth to normal speed and can quickly clear psoriasis symptoms, says Langley. Most responsive are plaque psoriasis, guttate psoriasis, and palm and sole psoriasis.
Side Effects
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The NPF says PUVA's most common short-term side effects are nausea, itching and skin redness, the last being not unlike exposure to sunlight.
Remedies
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The NPF recommends milk, ginger ale, ginger supplements and eating while taking oral psoralen to prevent nausea. Physicians counsel against PUVA if you have a skin cancer history.
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