Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
impĕtīgo (inp-), ĭnis, f. [impeto], a scabby eruption on the skin, impetigo, Cels. 5, 28, 17; Plin. 20, 1, 2, § 4; plur., id. 20, 9, 33, § 83; Col. 6, 31, 2.
As a disease of plants, Plin. 17, 24, 37, § 223.