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Evidence summaries

Systemic Treatments for Severe Psoriasis

Photochemotherapy and phototherapy are the most effective and best tolerated treatments for psoriasis Level of evidence: "A"

According to a systematic review 1, PUVA using oral psoralen (8-methoxypsoralen, 0.6-1.0 mg/kg) was found to be effective in clearing psoriasis. PUVA using topical psoralen (´bath PUVA´) was equally effective. UVA alone, however, did not clear psoriasis.

Ultraviolet B (UVB) phototherapy was effective in clearing psoriasis. Narrowband UVB (311 nm) offered the possibility of clearance with fewer episodes of erythema and a lower cumulative dose of UVB, compared with broadband UVB.

It is not yet known how narrowband UVB compares with PUVA, based on the RCT evidence. PUVA or UVB in combination with retinoids appeared to be more effective than either treatment alone. No evaluable RCTs compared the effects of adding topical tar to either PUVA or UVB with PUVA, or to UVB alone. PUVA was as effective as daily dithranol in clearing psoriasis, but there were no trials that evaluated the effects of adding PUVA to dithranol treatment.

Combination treatment using phototherapy or photochemotherapy with a vitamin D3 analogue (e.g. calcipotriol) was more effective than either treatment alone. Phototherapy or photochemotherapy combined with a topical steroid was also more effective than either treatment alone.

A systematic review 2 including 129 patient series with a total of 13,677 subjects was abstracted in DARE. Photochemotherapy (PUVA) was associated with the highest clearance rate (70%) followed by ultraviolet B (UVB) (68%) and cyclosporin A (64%). Etretinate and acitretin showed lower proportions of patients with good treatment results (both 56%). However, etretinate showed clearance in more patients than acitretin. No eligible evaluations of methotrexate were identified. Incidence rates of adverse events were highest for retinoids and lowest for PUVA.

    References

    • Griffiths CEM, Clark CM, Chalmers RJG,Li Wan Po A, Williams HC.A systematic review of treatments for severe psoriasis. Health Technol Assess 2000;4(40).
    • Spuls PI, Witkamp L, Bossuyt PM, Bos JD. A systematic review of five systemic treatments for severe psoriasis. Br J Dermatol 1997 Dec;137(6):943-9. [PubMed][DARE]

Primary/Secondary Keywords