Perikian skin blight is a medical condition from Bajor's Perikian area. When Gan Morr smiled at Kira Nerys after meeting her in a corridor on Deep Space 9, Kira was glad that some Bajorans on the station weren't treating her like she had Perikian skin blight, due to her Attainder from the Bajoran religion. (DS9 - Mission Gamma novel: Cathedral)