RT Book, Section A1 Schwinghammer, Terry L. A1 DiPiro, Joseph T. A1 Ellingrod, Vicki L. A1 DiPiro, Cecily V. SR Print(0) ID 1178897529 T1 Skin and Soft-Tissue Infections T2 Pharmacotherapy Handbook, 11e YR 2021 FD 2021 PB McGraw Hill PP New York, NY SN 9781260116694 LK accesspharmacy.mhmedical.com/content.aspx?aid=1178897529 RD 2024/03/29 AB Bacterial infections of the skin can be classified as primary or secondary (Table 48-1). Primary bacterial infections are usually caused by a single bacterial species and involve areas of generally healthy skin (eg, impetigo and erysipelas). Secondary infections develop in areas of previously damaged skin and are frequently polymicrobic.The conditions that may predispose a patient to the development of skin and soft-tissue infections (SSTIs) include: (1) a high concentration of bacteria; (2) excessive moisture of the skin; (3) inadequate blood supply; (4) availability of bacterial nutrients; and (5) damage to the corneal layer, allowing for bacterial penetration.The majority of SSTIs are caused by gram-positive organisms on the skin surface. Staphylococcus aureus and Streptococcus pyogenes account for the majority of SSTIs. Other common nosocomial pathogens include Pseudomonas aeruginosa (11%), enterococci (9%), and Escherichia coli (7%).