leprosy patients with less than five skin lesions are grouped into paucibacillary ( pb ) group for treatment purposes without taking into account their size and extent of lesions or the number of nerves involved ; the clinical classification of leprosy is not considered relevant .
they are uniformly treated with pb multidrug therapy for a fixed duration of 6 months as per who recommendations .
this group potentially consists of patients with diverse clinical , bacteriological , and histopathological features .
this categorization of leprosy based on the number of skin lesions for treatment purposes is arbitrary and is purely for the convenience of field workers . in 1998 , the who expert committee on leprosy proposed mdt - pb for leprosy patients with 1 - 5 skin lesions but did not mention any scientific basis for such a recommendation except citing the nonreliability of skin smear services , which were considered relevant till then . as per clinical classification for control programs of 1982 by who , bacterial index < 2 + on ridley scale was termed pb and that with bacterial index > 2 + was termed multibacillary ( mb ) .
this was changed in 1988 , in which bacterial index of zero was considered as pb and the ones with bacterial index of 1 + or above as mb
. there has been a substantial decrease in the numbers of leprosy patients after the implementation of mdt for leprosy . in the national leprosy elimination programme in india
, the proportion of mb cases was seen to increase in states heading toward elimination . however , this increase was marginal as pb cases still account for more than 60% of the leprosy cases in india in the year 2004 .
study of this pb group for variations and patterns is not only important in the present context , but also relevant in devising future strategies in leprosy control programs . in this study
, we analyzed the clinical , bacteriological , and histopathological features of this group of patients based on detailed clinical examination , skin smear findings , and skin histopathology .
thirty - one patients of leprosy with 15 skin lesions attending the department of dermatology , jjmmc , davangere , karnataka , over a period of 2 years were included in this study .
the diagnosis was based on the presence of hypopigmented hypoesthetic skin lesions and cutaneous and/or peripheral nerve thickening .
the sections were stained with hematoxylin and eosin ( h&e ) and modified fite stain , and studied by pathologist .
the type and character of granuloma and the presence of acid fast bacilli ( afb ) were noted .
the bacillary index of granuloma ( big ) was calculated in the tissue biopsy specimen .
of the 31 patients , 19 ( 61.2% ) had single skin lesions [ figure 1 ] , 7 ( 22.5% ) had two , 4 ( 12.9% ) had three , 1 ( 3.22% ) had four skin lesions .
their clinical classification was tuberculoid leprosy ( tt ) in 1 patient and borderline tuberculoid ( bt ) in 30 patients . slit skin smear ( sss ) for afb was negative in all patients .
well - defined raised erythematous lesion the histopathological findings of h and e stained skin biopsies were as follows : tt ( 1 ) , bt ( 23 ) [ figures 25 ] il ( 6 ) patients .
the big values on modified fite stain were 1 + in two biopsies which showed features of bt on histopathology [ table 1 ] .
pan dermal granuloma with langhans giant cells hugging the epidermis , h and e ; 4 initial sections 
lymphohistiocytic aggregate around nerve twigs , h and e ; 40 fite faraco stain  afb in nerve twig , h and e ; 40 skin biopsies with histopathological features and big in the bt group , 23 out of 30 patients showed concordance , i.e. , clinicopathological correlation was 76.6% .
clinicopathological correlation among 31 patients under study the percentage of positivity of afb was 0% in sss , and 6.45% in skin biopsies .
this study reveals that patients with 15 skin lesions present with varied clinical and histopathological features which points to the nonhomogeneous nature of this group .
two patients with clinical features of bt leprosy had big of 1 + on skin biopsy , which highlights the importance of fite faraco stain on skin biopsies which reveals the presence of m. leprae bacilli better than sss , thus indicating the importance of histopathology and afb stain on skin biopsy to rule out mb type in patients clinically grouped as pb type .
the significance of our observation is that patients with 15 skin lesions do not have disease of similar severity , and can reveal afb in few of them .
it is known that clinical features in leprosy patients reflect only the gross morphology of the underlying pathological changes .
significant discrepancies have been reported between the bacteriological and immunological status of the nerve and skin compared to the clinical diagnosis.[46 ] these features should also be considered while establishing treatment programs for leprosy .
it has been observed that a few bt patients harbor afb in their nerves for many years , even though they become clinically inactive following mdt .
bacterial clearing capacity within a lepromin - induced granuloma is not invariably present in all tuberculoid and indeterminate leprosy patients .
this study thus makes it mandatory to study tissue biopsy findings in all leprosy patients which were not considered relevant for treatment purposes until now , and thus could be given a status in the categorization and assessment of severity of the disease .
the significance of the finding of afb ( 1 + or more ) and histopathology of mb type of leprosy in tissue biopsies , in patients grouped as pb leprosy should be resolved so that these patients could be given the drug therapy and duration of therapy they warrant .
 background : patients with 15 skin lesions are clinically categorized as paucibacillary for treatment purposes . for betterment and adequate treatment of patients , 
 this grouping needs further study.aim:to study a group of leprosy patients with 15 skin lesions , compare clinical details with histopathological findings and bacteriological status of the skin to evaluate the relevance of this grouping.materials and methods : two - year study involving 31 patients of leprosy with 1 - 5 skin lesions was included in this study . 
 a number of skin lesions were recorded . 
 skin biopsies were taken in all patients . 
 the biopsies were evaluated for the type of pathology and acid fast bacilli ( afb ) status.results:of 31 patients , 19 ( 61.2% ) had single skin lesion , 7 ( 22.5% ) had two lesions , 4 ( 12.9% ) had three lesions , and only one ( 3.22% ) had four lesions , there were no patients with five lesions . 
 of the 31 patients , 30 ( 96.7% ) were clinically diagnosed as borderline tuberculoid and one patient ( 3.22% ) has tuberculoid leprosy . 
 skin smears were negative for afb in all patients . 
 the histological diagnoses were : tt 1 ( 3.22% ) , bt 24 ( 77.41% ) , and il 6 ( 19.2% ) . 
 afb were found in 2 ( 6.45% ) out of 31 skin biopsies . 
 clinicopathological correlation was 76.6% in the bt group.conclusion:tissue biopsy findings in 15 skin lesions which were not considered relevant for treatment purposes until now should be given a status in the categorization and assessment of severity of the disease . 
 the significance of finding of afb and histopathology of multibacillary ( mb ) type of leprosy in tissue biopsies , in patients grouped as pb should be resolved so that patients could be given the drug therapy and duration of therapy they warrant . 