AIDS patient with drug allergy. Patient's blister- ed lip due to a reaction to the antibiotic drug tetracycline. This condition is also known as a fixed drug eruption and always affects the same area of the body, although repeated use of the drug leads to more severe symptoms. AIDS (acquired immune deficiency syndrome) is a disease caused by the human immunodeficiency virus (HIV). It causes weakening of the immune system, making the patient susceptible to opportunistic infections and making normally harmless infections life threatening. In Africa, where this patient is from, lack of access to a variety of drugs makes AIDS a major public health concern.