Lepromin test is positive in which leprosy –
As you know, lepromin test is cell mediated hypersensitivity (delayed or type IV), and the maximum suppresion of cell mediate immunity occurs in polar lepromatous leprosy → Lepromin test is negative in lepromatous leprosy. Maximally preserved cell mediated immunity is seen in tuberculoid leprosy → Lepromin test gives strongest reaction in polar tuberculoid (TT) leprosy.

Lepromin Test
TT : ++
BT  : +
BB : +/–
BL : –
LL : –
IL : +/–
Lepromatous
Indeterminate
Histoid
Tuberculoid