Precipitation of type-I (upgrading) reaction in leprosy by skin testing with antigen and irritants

Twenty patients of various types of leprosy were skin tested with lepromin, PPD and DNCB to assess their immunological status. Two of the twenty (18 BT; 2 BB) patients belonging to BT type developed signs of acute neuritis of sudden onset about 4 weeks after the test with DNCB, lepromin and PPD. The patients were on DDS therapy already for the last 3-4 months. Presumably DNCB, PPD or lepromin testing had precipitated the reaction. A suggestion is made that lepromin a lower concentration could be used initially and if it gives negative reaction, a higher concentration may be used as in case of PPD testing, particularly in TT and BT cases already put on treatment.