Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† ĕrysĭpĕlas, ătis, n., = ἐρυσίπελας, a reddish eruption on the skin, St. Anthony’s fire, erysipelas, Cels. 5, 28, 11 (id. 5, 26, 31 and 33, written as Gr.).