infections
Leprosy
Diagnosis of Leprosy
Examination of a sample of infected skin tissue Doctors may suspect leprosy based on symptoms, such as distinctive rashes that do not disappear, enlarged nerves, loss of the sense of touch, and deformities that result from muscle weakness. But in the United States, doctors may not think of leprosy right away because it is rare and they are unfamiliar with its symptoms. Examination of a sample of infected skin tissue under a microscope (biopsy) confirms the diagnosis. Because leprosy bacteria do not grow in the laboratory, culture of tissue samples is not useful. Blood tests to measure antibodies to the bacteria have limited usefulness because antibodies are not always present. (Antibodies are produced by the immune system to help defend the body against a particular attacker, including leprosy bacteria.) 