Human Immunodeficiency Virus (HIV) Infection and Acquired Immune-Deficiency Syndrome (AIDS) at a Glance
- As of 2008, more than 30 million people were living with HIV infection/AIDS.
- HIV-1 and HIV-2 are human lymphotropic retroviruses that principally infect CD4+ T lymphocytes and CD4+ cells of monocytic lineage.
- An individual is deemed to have AIDS if he or she is HIV-seropositive with a CD4+ T cell count <200/μL, a CD4+ T cell percentage <14, or any of several diseases deemed to be indicative of a severe defect in cell-mediated immunity.
- The broad and diverse spectrum of dermatologic disease in HIV infection/AIDS includes inflammatory, infectious, neoplastic, and medication-related disorders.
- Specific stages of HIV disease (acute HIV syndrome, immune reconstitution, clinically latent disease, and advanced disease) tend to be associated with different dermatologic disorders.
- Dermatologic disease may help to estimate the level of immunosuppression in HIV infection/AIDS, particularly in resource-limited settings.
- As there are many dermatologic disorders that are seen in HIV infection/AIDS, this chapter focuses on those diseases that are the most closely associated.
The introduction of antiretroviral therapy (ART) has markedly altered the life expectancy and quality of life for many of the 33.4 million individuals worldwide infected with human immunodeficiency virus (HIV).1 However, the number of newly diagnosed infections remains high, and many individuals in areas of high HIV prevalence remain unaware of their infection. Globally, 2.7 million new infections were estimated to have developed in 2008, while 56,300 new infections were estimated to have occurred in United States in 2006.1, 2 It is estimated that 21% of the 1.1 million infected HIV individuals in the United States are currently undiagnosed.2,3 This suggests that identification of HIV infection/acquired immune-deficiency syndrome (AIDS)-associated dermatoses has the potential to facilitate the diagnosis of HIV infection not only in resource-limited settings but in relatively resource-abundant ones.
Cutaneous disorders occur in nearly every patient during the course of HIV disease, either as a result of acquired immunodeficiency or from treatment. The spectrum of dermatologic manifestations of HIV disease is broad and diverse.4 Individuals who have access to combination ART have a markedly altered course of disease if immune restoration is successfully achieved.5 In most cases, there is a marked reduction in the incidence of opportunistic infections and neoplasms. Globally, however, the majority of HIV-infected individuals lack access to ART and, consequently, many of the cutaneous manifestations associated with HIV disease become chronic and progressive.
HIV is a lymphotropic human retrovirus, which is predominantly transmitted through sexual contact. Other important means of transmission include exposure to infected blood (including needles shared by injecting drug users and “skin popping”) and transmission from an infected mother to her infant during pregnancy, delivery, or breastfeeding. HIV-1 is the most common cause of HIV infection globally, whereas HIV-2 infection has been detected mainly in West Africa. Although both HIV subtypes cause clinically similar disease, HIV-2 is associated with slower progression of immunosuppression, decreased infectivity, and resistance to non-nucleoside reverse transcriptase inhibitors.6–8