EFFECT OF SUNLIGHT ON THE CLINICAL MANIFESTATIONS OF PELLAGRA

Abstract

The influence of the sun's rays on the lesions of pellagra has been a subject of debate for nearly two hundred years. Casal¹ noted a seasonal variation in the incidence of pellagra, with a peak which corresponded to the spring equinox. In Italy one of the common names applied to this disease by the peasants is mal del sole (disease of the sun), while certain Italian physicians have described the lesions as due to "sunstroke of the skin."² Many modern clinicians³ have stated their conviction that there is a close relationship between exposure to sunlight and the development of cutaneous lesions in a pellagrin. Various observers⁴ have produced typical cutaneous lesions in pellagrins by exposing normal or recently healed areas of skin to direct sunlight. Gherardini^3w demonstrated the effect of the sun by systematically uncovering various parts of the body of each patient. Bouchard,^3b Hameau^3x and Ormsby^4a