Type of leprosy

Clinical criteria

Histological criteria

TT

Well defined dry, atrophic scaly patch/plaque with near total/total loss of sensation

 Well formed epithelioid cell

Granulomas  distributed through

out the dermis,  encroaching/eroding the  epidermis along  with destruction of  nerve and adnexal structures

BT

Well defined patch/plaque with moderate loss of sensation and presence of satellite lesions

 Well to ill defined granulomas

having fewer number of lymphocytes and more giant

cells and not encroaching upon the epidermis

BB

Multiple annular/geographic/bizarre shaped plaques with minimal loss of sensation

Loosely arranged granuloma consisting  epithelioid cells, few macrophages with scanty lymphocytes

BL

Multiple hypopigmented/coppery coloured small to medium sized patches or papules tending towards symmetry

Asymmetrical nerve enlargement

Ill defined granuloma  rich in foamy histiocytes with admixture of few epithelioid cells

LL

Numerous hypopigmented/coppery coloured, shiny patches /papules /nodules with normal sensation

Symmetric enlargement of nerves

Infiltration of both ear lobes

Diffuse macrophage granuloma consisting of  foamy histiocytes with prominent Grenz zone and positive for AFB

IL

 Ill to well defined hypopigmented non scaly patch with or without loss of sensation persisting for more than 6months

Mild lymphocytic infiltration around nerve bundles, sweat glands and arrector pili muscle