Cutaneous tuberculosis, different clinical spectrum of the same disease: the importance of pre-test probability

Antecedents. This report presents three cases of Cutaneous tuberculosis CTB that were diagnosed at Calderon Hospital, Quito, Ecuador. The first case was Tuberculosis verrucosa cutis (TVC) in a 44-year-old man with circinated erythematous areas with ulcerated nodules and verruciform plaques from the right lower limb to the hip. The second case was Lupus Vulgaris (LV) in a 50- year-old female with one-year history of pruritic dermatosis in the left ciliary area. The third case was Scrofuloderma in a 23-year-old man with erythematous nodules that drain caseous material at neck, thorax and axillary region. Almost all laboratory tests that were available turned out to have limitations as a diagnostic tool. Conclusion. In immunocompromised and high-risk individuals with atypical lesions, it is important to correlate clinical and epidemiological characteristics with the pretest probability in order to optimize indicators and determine or exclude out the diagnosis.