• A 27-year-old woman exhibited an urticaria only to monochromatic light in the range from 400 to 525 nm, but not to polychromatic light longer than 360-nm ultraviolet (UV) and visible light. An urticarial response induced by 475-nm monochromatic light was completely inhibited by preirradiation, simultaneous irradiation, and postirradiation with light having wave bands longer than 650 nm. Two other patients with sunlight-induced solar urticaria, who had an erythema-and-wheal reaction during and after exposure to sunlight, had no suppressive wave bands in either the UV or visible-light range. These observations strongly indicate an important role for inhibition wave bands in the development of light-induced immediate erythema and urticaria. In some cases of solar urticaria, preirradiation and postirradiation with longer visible light wavelengths could be useful in preventing the development of urticaria.
(Arch Dermatol 1985;121:503-507)
Ichihashi M, Hasei K, Hayashibe K. Solar UrticariaFurther Studies on the Role of Inhibition Spectra. Arch Dermatol. 1985;121(4):503-507. doi:10.1001/archderm.1985.01660040087017