The Utility of Laser Thermometry in Grading Plaque Psoriasis

Abstract

Characteristics of psoriatic plaques may affect thermoregulation and the temperature of psoriatic lesions. This study assessed the utility of handheld laser thermometry in evaluating the severity of psoriatic plaques. Twenty-five patients with plaque psoriasis were examined with temperature measurements performed on psoriatic plaques, adjacent normal-appearing skin and normal-appearing contralateral skin. Scaly regions of psoriatic plaques were, on average, 1.6° F cooler than non-scaled regions. Non-scaled plaque regions were 0.5° F cooler than both adjacent and contralateral skin, on average. Sixty-six percent of plaques were cooler than contralateral skin. None of these temperature differences was statistically significant. The thickened plaque stratum corneum may have provided a less penetrable outer layer, preventing reading the true underlying temperature. We conclude that given its ease of use, handheld laser thermometry may yet be a useful plaque assessment method. Further studies are warranted.