International Journal of Leprosy Official Organ of the International Leprosy Association

The relation of allergic and immunologic phenomena in leprosy and tuberculosis has been the subject of much speculation and intensive study. Since Fernandez,l-in 1939, published his observations on the comparative study of the reactions to tuberculin and to lepromin in different subjects, many contributions to the subject have been made and great hopes have been entertained of the possibility of discovering a practical method of raising the defenses of the human body against infection with Mycobacterium leprae. The original Mitsuda test, and later those performed with the purified bacillary antigens of Fernandez and of Dharmendra, showed that the human skin has a capacity to react against these antigens under certain conditions, and that in the case of persons infected with the leprosy bacillus who react positively the disease assumes the benign tuberculoid type. It is also believed by many, although it is still subject to actual proof, that normal persons who react positively are well protected against infection.