Of ten untreated patients with lupus erythematosus subjected to repeated exposures of monochromatic ultraviolet light at 300 nanometer (nm) wavelength, four developed lupus erythematosuslike lesions resembling the patient's natural disease, while four developed a persistent erythema at the test site, and the other two revealed only a normal sunburn response. Of five patients with lupus erythematosus being treated with quinacrine, normal responses were obtained in four and a persistent erythema was observed in the fifth.
Clinically and histologically the lupus erythematosus-like lesions resembled the naturally occurring skin lesions of lupus erythematosus in each patient. The persistent erythemal reactions manifested acanthosis, edema, and cellular infiltration but did not show histologic changes characteristic of lupus erythematosus. Exposure to long-wave ultraviolet and visible light of 340, 360, 400, and 500 nm wavelengths produced no visible response.
Freeman RG, Knox JM, Owens DW. Cutaneous Lesions of Lupus Erythematosus Induced by Monochromatic Light. Arch Dermatol. 1969;100(6):677-682. doi:10.1001/archderm.1969.01610300027004