When the immune system becomes comprised, the leisions become more and more numerous and less discrete. The bacilli increase in number and the immune responsiveness decreases. Tactile sensory loss diminishes towards the anergic pole in this state. There is a borderline tuberculoid form, borderline leprosy form and borderline lepromatous form. This is the earliest clinical evident form of the disease.
Patients present one or more skin lesions of variable appearance.
Upon microscopic examination, patient cells reveal a monocellular infiltration around capillaries and skin appendages. There is usually a proliferation of the Schwann cells of the dermal nerves. In the majority of patients the indeterminate lesions heal, but in twent five percent of cases, the disease progresses to another level.