This rarely occurs however, as the skin of a patient is remarkably free of bacteria. Although the disease is communicable, it is by far one of the least. Minimized incubation periods of just a few weeks have occurred among young infants. Each specific type of Hansen's disease has its own set of symptoms. Tuberculoid leprosy creates well-defined skin lesions that are numb to the touch, hypopigmented, and may take up to four years to form.
Lepromatous leprosy creates both skin lesions and nodules as well as a chronically stuffy nose.
Lepromatous symptoms may take up to eight years to form. Diagnosis of Hansen's disease is usually based on the symptoms described above as they are easily observed. Rarely are lab techniques used in diagnosis. In tuberculoid leprosy very few, if any, antibodies against the bacteria circulate against the bacteria. Research has indicated that M. leprae is capable of interfering with macrophage function in skin lesions and preventing the proliferation of T-cells.