A randomised study of beta-carotene/canthaxanthin or placebo in chronic plaque psoriasis has failed to show any significant difference in the time to clearing and in the total accumulative dose required. Orange discolouration and hyperpigmentation of the skin occurred in the test group. In patients studied outside the randomised comparison, 2 patients who had not been able to tolerate PUVA therapy because of burning were subsequently able to do so when beta-carotene/canthaxanthin was added to their treatment regimen.
