We systematically reviewed the evidence concerning the ability of five
systemic treatments to induce remission in patients with severe psori
asis: ultraviolet B (UVB), photochemotherapy (PUVA), methotrexate (MTX
), retinoids (RET) and cyclosporin A (CYA), An elaborate literature se
arch was performed. the validity of studies was assessed, and data wer
e analysed, In total, 89, 193, 101, 155 and 127 studies (n = 665) conc
erning UVB, PUVA, MTX, RET and CYA were found. The exclusion rate was
high, mainly because of concomitant antipsoriatic therapy, outdated do
sages or inadequate documentation. No study on MTX could be included.
A total of 129 patient series was included in the analysis, reporting
on 13,677 patients. Study size-weighted averages of the proportions of
patients with clearance and good, moderate and poor response (defined
, respectively, as 95-100%, 75-100%, 50-75% and < 50% reduction in the
outcome measurements as compared with baseline) were calculated, PUVA
therapy was associated with the highest average proportion of patient
s with clearance (70%), and the highest proportion of patients with go
od response (83%), followed by UVB (68%) and CYA (64%). Incidence of s
ide-effects per week was highest in the RET group and lowest in the ph
ototherapy groups. This review may provide a basis for the development
of guidelines for the treatment of psoriasis, Trials comparing oral m
odalities applied according to currently accepted standards should als
o be carried out.