Tuberculosis of the skin: historical perspectives on tuberculin and Bacille Calmette Guérin.

The article presents information on tuberculosis (TB) of the skin and its treatment. Researcher Robert Koch reported on his bacteriological findings on TB in 1882. He stained and cultured tubercle bacilli and reported the transfer of TB to animals with these cultures. With these methods, he demonstrated that tubercle bacilli cause the various lesions of TB, including scrofula, associated with lupus vulgaris. Koch's postulates, which derive from his findings on tubercle bacilli, provide the key methods for identifying the causative agent of scrofula, lupus vulgaris, and related forms of TB of the skin.