Many different schedules for delivery of phototherapy to people with psoriasis are in current use. One systematic review of treatments for severe psoriasis25 concluded that:
• photochemotherapy (PUVA) using a combination of either oral or topical psoralen with UVA was effective in clearing psoriasis
• oral and topical PUVA were of comparable efficacy
• UVA alone did not clear psoriasis
• broad-band 290-320 nm ultraviolet B (BBUVB) was effective in clearing psoriasis
• narrow-band 311 nm UVB (NBUVB) offered the possibility of clearance with fewer episodes of erythema and may require a lower cumulative dose of UVB to achieve this
• PUVA or UVB in combination with systemic retinoids appeared to be more effective than either therapy alone
• it was not possible to reach a conclusion on the effects of combining topical tar or anthralin with phototherapy
• PUVA is of similar efficacy to daily anthralin dressings in clearing psoriasis
• combinations of either UVB or PUVA either with vitamin D3 analogues or with topical corticosteroids all appeared to be superior to each agent used alone.
More recent evidence suggests that NBUVB phototherapy used three times weekly is of similar efficacy to twice-weekly PUVA.26
There is little evidence to support the use of balneophototherapy in which phototherapy is combined with bathing in various mineral or salt waters.27 Heliotherapy using natural sunlight is effective at clearing psoriasis28 but is associated with an increased risk of skin cancer.29 The main risks of PUVA therapy are photoageing (premature skin ageing) and skin cancer, notably squamous cell carcinoma30 and, to a lesser extent, malignant melanoma.31 It is therefore advisable to limit the number of treatments to 200 or the cumulative UVA dose to 1500 J/cm.2,32 Therapeutic BBUVB irradiation does not appear to be associated with development of skin cancer. There are no long-term studies to assess whether NBUVB carries a risk of skin cancer.
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Complete Guide to Preventing Skin Cancer. We all know enough to fear the name, just as we do the words tumor and malignant. But apart from that, most of us know very little at all about cancer, especially skin cancer in itself. If I were to ask you to tell me about skin cancer right now, what would you say? Apart from the fact that its a cancer on the skin, that is.