Changing pattern of cutaneous tuberculosis. A prospective study.

During the past 3 years, we have seen a changing pattern of cutaneous tuberculosis, in which its incidence was recorded to show an upward trend affecting predominantly the adult men. The latter was true in reinfection--lupus vulgaris and tuberculosis verrucosa cutis, whereas a substantial number of children were victims of reactivation--scrofuloderma. The duration of the disease was usually short in reactivation tuberculosis. Its clinical expression, however, conformed largely to the ritual text except that apple-jelly nodules were infrequently demonstrated. Similarly, the morbidity was low. The affliction of the extremities in lupus vulgaris, in particular, was a contrasting feature. The histopathology invariably either confirmed or supplemented the clinical impression. The ultimate confirmation of cutaneous tuberculosis was done only by the demonstration of Mycobacterium tuberculosis in smears, or its recovery in vitro. In view of the limitations of the preceding parameters, the diagnosis may reasonably be made based on the history and evolution of the disease, cardinal morphologic features of reinfection and reactivation tuberculosis, and histopathologic characteristics. A response to antitubercular drugs may be of assistance.