Though the pathogenesis of psoriasis has been studied extensively, data from the multitude of trials presented at a scientific meeting last week shows that no one has yet found a magic bullet. While psoriasis might be an indication that could be revolutionized by the identification of patient cohorts that respond better to particular types of treatment, until that information surfaces, treatment is likely to consist of combinations of drugs.

Psoriasis lesions, which are characterized by thickened, scaly and inflamed skin, originally were thought to arise from primary disorders of keratinization that led to local inflammation. However, it is now believed that the opposite is true: autoreactive T lymphocytes cause local inflammation with resultant angiogenesis and increased proliferation of keratinocytes.