The anatomical distribution of single leprosy lesions in an African population, and its implications for the pathogenesis of leprosy

Abstract

Data on the anatomical sites of single leprosy lesions found in 635 newly diagnosed and biopsy-confirmed leprosy patients are presented. These patients were found during total population surveys carried out by the Lepra Evaluation Project, a prospective longitudinal study of the epidemiology of leprosy in Karonga District, Northern Malawi. There was a striking excess of single lesions on the face and the back of the arms, compared to the distribution of skin surface area, and a deficit on the legs, regardless of age. There is some evidence for a sex difference in lesion distribution among adults, with fa cial and arm lesions being relatively more common in fe males and back lesions being more common in males. The excess oflesions on the face compared to the lower limbs is similar to data from Uganda, but very unlike data from Burma and elsewhere in Asia. Overall, the distribution of lesions does not suggest a pattern reflecting entry of My cobacterium leprae, nor does it suggest an association with anatomical distribution of the nervous or vascular system. It is argued that the distribution reflects the influence of some 'local' environmental or behavioural factors. 242 0305-75 1 8/90/06 1000 +09 SO LOO

Inoculable leprosy

“…Mycobacterium leprae has also been observed in the epidermis and in epidermal washings of multibacillary leprosy cases 6,10–12 . The first leprosy lesion, probably the point of the organism's entry, commonly occurs on exposed trauma‐prone body parts 13 …”

Single lesion as an indicator to monitor the leprosy trend to elimination in hyperendemic areas

“…In Palmas, incidence rates for males and females did not show important differences 3 . Ponnighaus et al 33 showed that skin lesions in females are more frequently found on the face and arms as compared to males. These differences in lesion location facilitate the identification of early leprosy in women.…”

The epidemiology of leprosy in Karonga District, northern Malawi 1973–2023: An analysis of leprosy’s distribution, risk factors, control and decline in rural Africa

“…Percentages refer to the proportion of all single lesions, in males and females separately, and the proportion of total body surface area, on each anatomical site. 53 a detailed clinical description of the lesion from which a biopsy was taken, including results of sensory testing. This resulted in a policy shift in late 1985 so that the histopathologist was thereafter told only the location on the body from which the biopsy was obtained.…”