Despite a widely held belief that the use of
emollients prior to broad-band UVB irradiation accelerates clearance of
psoriasis, only one single-blind controlled study exists in support of this. No similar study has been carried out with
photochemotherapy (PUVA) or narrow-band UVB (311-313 nm)
phototherapy. As some
emollients absorb UV radiation, and thereby inhibit
psoriasis clearance, there is a need to identify
emollients suitable for pre-irradiation use.
Coconut oil may be useful in this respect. In two randomized groups of patients with chronic plaque
psoriasis undergoing either routine PUVA (n = 14) or narrow-band UVB
phototherapy (n = 15), a single-blind controlled (half-body) study was undertaken to assess the effect of pre-irradiation application of
coconut oil. Patients were given PUVA twice weekly, or TL-01
therapy thrice weekly. The initial UV dose was 70% of previously determined minimal phototoxic (MPD) or minimal
erythema doses (MED), with 40% incremental steps at each visit (reduced if adverse effects occurred).
Psoriasis severity was scored on each side after every three treatments. No significant acceleration of
psoriasis clearance was seen in either group. We do not, therefore, recommend the routine use of
emollients prior to PUVA or TL-01
therapy when using near erythemogenic irradiation regimens.