Although psoriasis is perceived to have a limited effect on the cost of US healthcare, the reality is very different. Psoriasis is a persistent and progressive skin disorder that affects about 6 million people in the US, with 250 000 new cases diagnosed every year. Depending on disease severity, annual outpatient care can cost $US1400-$US6600 per patient, representing a total national cost of $US3.2 billion/year in the US. According to investigators from Health Economics Research, New Jersey, US, the high cost of care for selected patients with mild-to-moderate psoriasis can be reduced by using the new topical retinoid tazarotene. At the recent 56th Annual Meeting of the American Dermatology Association [Orlando, US; Mar 1998], the investigators presented the results of a pharmacoeconomic model of monotherapy with either tazarotene, fluocinonide or calcipotriol for patients with mild-to-moderate stable plaque psoriasis.*