Over the last 30 years, the landmark PUVA [psoralen–UV-A] Follow-up Study has demonstrated the importance of clinical epidemiology research in making informed treatment decisions for patients with psoriasis. When PUVA was first introduced, psoriasis was widely believed to be an epidermal cell proliferation disorder, and there were few systemic treatment options available at that time.1 Thirty years later, psoriasis is believed to be an immunologic disorder, and more new systemic therapies have been approved to treat it in the last 4 years than in the previous 30 years combined.2- 8 Our objective criterion regarding which patients have severe psoriasis and therefore are candidates for systemic therapy has also evolved during this period, declining from 20% to 30% body surface area (BSA) in the 1970s to 1990s to 5% more recently.9,10 With the increasing recognition of the impact of psoriasis on health-related quality of life and the advent of novel therapies targeting its immunopathogenesis, the treatment of psoriasis is undergoing a revolution. As patients with psoriasis are increasingly being treated with systemic agents on a long-term basis, the PUVA study provides an important reminder of the challenge involved in making clinical decisions based on a scientific understanding of the disease's natural history and the robust long-term safety and efficacy data of its treatments.
Gelfand JM. Long-term Treatment for Severe PsoriasisWe're Halfway There, With a Long Way to Go. Arch Dermatol. 2007;143(9):1191-1193. doi:10.1001/archderm.143.9.1191