Therapy of HIV infection has undergone significant changes since the introduction of highly-active antiretroviral therapy (HAART). Mortality and the appearance of opportunistic infections have significantly been reduced. Diseases of the skin and adjacent mucous membranes often provide the first signs for HIV infection. The spectrum of dermatologic findings related to HIV includes a variety of cutaneous and mucocutaneous disorders. The most frequent diagnoses are oral candidiasis, mollusca contagiosa, oral hairy leuokoplakia, herpes zoster and herpes simplex, seborrheic dermatitis, and Kaposi's sarcoma. Incompatibility reactions to drugs are observed on a strikingly frequent basis in HIV infection. Such severe incompatibility reactions are much more frequent in HIV patients than in the normal population. Inducers often include sulfonamides, cotrimoxazole, tuberculostatics as well as nucleoside-type reverse transcriptase inhibitors.