19.1  Classification of leprosy

Classification of leprosy patients is based on the clinical features (see Table 19.1). The World Health Organization (WHO) distinguishes between two major types, one of which (multibacillary leprosy) was introduced in Study Session 18. Paucibacillary leprosy is characterised by the low number of skin lesions and the low number (or absence) of visible Mycobacterium leprae in microscope slides taken from these patients.

Table 19.1  Classification of leprosy types.

Clinical featuresPaucibacillary (PB)Multibacillary (MB)
Skin lesionsOne to five lesionsSix or more lesions
Nerve damageOnly one nerve involvedTwo or more nerves involved

Paucibacillary is pronounced pore-see-bass-ill-ary’. Pauci comes from the Latin word meaning ‘few’.

Learning Outcomes for Study Session 19

19.2  Multidrug therapy (MDT) for the treatment of leprosy