Macular lesions in leprosy: a clinical, bacteriological and histopathological study.

Among 150 untreated patients of leprosy, 19 had only macular lesions; three were of the indeterminate type, and eight each were of the tuberculoid and the borderline types, according to the Indian Association of Leprologists (IAL, 1981) classification. The clinical, bacteriological, and histopathological parameters of these 19 patients were studied both before and after six months of WHO Multi Drug Therapy (MDT/1982). A single macule was present in seven (36.84%) patients. In twelve (63.16%), two or more were seen. In eighteen (94.74%), one or more peripheral nerves were enlarged. The size of the macules varied from 5 to 15 cm, and there were no changes seen even after treatment. In most (94.74%) of the patients, the macules were hypopigmented. The surfaces were rough and dry in seven (36.84%) but smooth in the other twelve (63.16%). The margins were well defined in the seven (36.84%) patients with single macules but ill defined in the other twelve (63.16%). After six months of antileprosy treatment, the single macules showed some resolution. Slit skin smear examination was negative in all cases before and after treatment. Clinico-histopathological correlations were seen in only six (31.58%) patients; the clinical diagnoses were indeterminate and tuberculoid leprosy in three (15.79%) patients each. In the indeterminate group, the clinico-histopathological correlation was 100%; it was 37.50% in the tuberculoid group. There were no correlations between the clinical and histopathological parameters in thirteen (68.42%) cases. After six months of treatment, the histopathology became nonspecific in all patients. The lepromin test was positive in six (31.58%) patients; four were of the tuberculoid group and one each from the indeterminate and borderline leprosy groups. Hence, although macular lesions can be seen throughout the leprosy spectrum, it is difficult to correlate their clinical, bacteriological and histopathological parameters.