Abstract
Ultraviolet radiation (2850 to 3150 A range) produces abnormal cutaneous reactions and exacerbation of systemic manifestations in subacute and acute systemic lupus erythematozus. It may also be responsible for cutaneous lesions and systemic involvement in rare cases of chronic discoid lupus erythematozus[long dash]probably those with disseminated lesions. The pathophysiological mechanism producing these photobiological effects in lupus erythematozus remains unknown.