Psoriasis

Measuring improvement in psoriasis, while seemingly straightforward, remains a perplexing problem. It is relatively easy to estimate the amount of the body covered with psoriatic plaques; however, this measurement does account for the severity of the lesions involved. Moreover, the severity of the disease can be distinct from the number or size of lesions. A recent consensus conference of the American Academy of Dermatology emphasized that any determination of the severity of psoriasis requires special attention to the impact of the disease on the patient's quality of life [1]. Since the impact of psoriasis may differ from one patient to the next, any physical measurement of psoriasis will necessarily be an incomplete assessment of the severity of the disease. In this chapter, the commonly used techniques for measuring the clinical severity of psoriasis will be discussed. The critically important measures of quality of life are reviewed in Chap.VIIA.