Chronic polymorphic light eruption. Particular wavebands and the effect of carotene therapy

Forty patients with chronic polymorphic light eruption (CPLE) were tested with the Osram High Pressure Xenon (XBO 150 W) lamp. The tests were performed with unfiltered light, with the Schott WG320 filter for wavelengths above 320 nm and with Schott filters for 310 nm and 361 nm. Abnormal reactions, i.e. lowered MED, papular response or reactions to long wave UV light were observed in almost all patients. A papular response was obtained in more than 50%. With a Schott KG1 filter, which particularly reduces the amount of infrared radiation, there was a great reduction in number of responses. The effect of carotene therapy was evaluated in 17 patients. The therapy had a beneficial effect of low significance only in the case of unfiltered light and not for any particular waveband. Some patients showed clearly an increase in tolerance to sunlight, but this was not related to the plasma level of carotene.