The immune compromised host in the twenty-first century: management of mucocutaneous infections.

Infectious diseases encountered in dermatology have changed tremendously during the past few decades with the emergence of the immunocompromised host. This change is a result of the human immunodeficiency virus epidemic, use of immunomodulating drugs, bone marrow transplantation, increasing prevalence of diabetes mellitus, and an aging population. New pathogens have been discovered and new disorders have occurred. In the compromised host, infection can be more aggressive and widespread locally, be caused by opportunistic pathogens, and be disseminated hematogenously from or to the skin. The prevalence of nonmelanoma skin cancer has increased, and squamous cell carcinomas can be more aggressive with more rapid local growth as well as frequency of metastasis.