A biopsy that shows well-formed granulomas but only very few organisms establishes the diagnosis. A patient with lepromatous leprosy can serve as the host for an enormous bacterial burden because organisms multiply unchecked. The numerous symmetrical skin lesions are small and ill defined. At times, the entire skin surface can be involved, yielding a diffuse, waxy appearance. The loss of eyebrows and hypertrophy of earlobes produce the characteristic leonine facies.
Neurologic involvement is widespread.
If untreated, lepromatous leprosy is relentlessly progressive. Many patients have a type of leprosy that falls between the tuberculoid and lepromatous forms and are classified as having borderline, or dimorphous, leprosy. In addition, the otherwise chronic course of leprosy can be punctuated by acute inflammatory reactions called erythema nodosum leprosum and the lepra reaction. Patients should be treated by physicians experienced in the management of this disease. Sulfones have been the mainstay of chemotherapy, but primary dapsone resistance has led to recommendation for combined chemotherapy with rifampin and clofazimine.