to have inflammation in the (finger/toe) nail (the tissue below the nail is agitated) (see Molina)
Alonso de Molina:
mautztemi. ni. (pret. onimautzten.) tener panarizo en la uña. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 54v. col. 1. Thanks to Joe Campbell for providing the transcription.