Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
impĕtīgĭnōsus (inp-), i, m. [impetigo], one who has the impetigo, Dig. 21, 1, 6, § 6; cf. impetiginosus λειχηνωτός, Gloss. Philox.
Also: ‡ impetix impetigo, Paul. ex Fest. p. 109 Müll.