Lupus vulgaris: report of two cases.

Although there has been a steady decline in the incidence of tuberculosis in recent years, it persists in some regions, and where AIDS is especially prevalent, the number of new cases has been increasing. Thus, cutaneous tuberculosis has re-emerged in areas with a high incidence of HIV infection and multidrug-resistant pulmonary tuberculosis. Lupus vulgaris has been and remains the most common form of cutaneous tuberculosis. Cutaneous manifestations of disseminated tuberculosis are unusual, being seen in less than 0.5% of cases. Scrofuloderma, tuberculosis verrucosa cutis and lupus vulgaris comprise most cutaneous tuberculosis cases. Bacillus Calmette-Guerin (BCG) is derived from an attenuated strain of Mycobacterium bovis and is employed beneficially as a relatively safe vaccination in Poland and other countries in which the prevalence of tuberculosis is high. However, BCG vaccination may produce complications, including disseminated BCG and lupus vulgaris, the latter seen in one of our two patients in whom lupus vulgaris at the inoculation site followed a second vaccination with BCG 12 years after the initial one. A similar phenomenon has been described after immunotherapy with BCG vaccination. Re-infection (secondary) inoculation cutaneous tuberculosis may also occur as a result of BCG vaccination, producing either lupus vulgaris or tuberculosis verrucosa cutis, probably depending upon the patient's degree of cell-mediated immunity. However, most lupus vulgaris cases are not associated with vaccination with BCG, as occurred in our first patient. For those who do develop lupus vulgaris, it can be persistent for a long period, in some cases for many decades. In the second patient we describe a lengthy duration and cutaneous reactivation at distant sites after more than 40 years.