TY - CHAP M1 - Book, Section TI - Chapter 185. Actinomycosis, Nocardiosis, and Actinomycetoma A1 - Bravo, Francisco G. A1 - Arenas, Roberto A1 - Sigall, Daniel Asz A2 - Goldsmith, Lowell A. A2 - Katz, Stephen I. A2 - Gilchrest, Barbara A. A2 - Paller, Amy S. A2 - Leffell, David J. A2 - Wolff, Klaus PY - 2012 T2 - Fitzpatrick's Dermatology in General Medicine, 8e AB - Actinomyces and Nocardia are a group of filamentous bacteria belonging to the same class, Actinobacteria, and same order, Actinomycetales. They cause human disease with prominent skin involvement. Microorganisms under this category were wrongly classified as fungi for a long time, because of their tendency to produce branching filaments, mimicking radiating hyphae (from the Greek actino, meaning sun). Their taxonomy is still evolving, resulting in continuous reclassification of different species in old and new families. Anaerobic endogenous Actinomyces, part of our normal respiratory, intestinal, and genitourinary flora, will cause localized suppurative disease with fistula formation that is analogous to the lumpy jaw of cattle. Aerobic environmental Nocardia sp. cause diseases ranging from cellulitis to paronychia to abscesses, with the most striking presentation being a lymphocutaneous, sporotrichoid syndrome. In addition, other aerobic environmental species of Nocardia and Actinomyces will cause one of the two known forms of mycetoma, the actinomycetoma. SN - PB - The McGraw-Hill Companies CY - New York, NY Y2 - 2024/03/28 UR - accessmedicine.mhmedical.com/content.aspx?aid=56084611 ER -