Tuberculous gumma (scrofuloderma) seen mostly on:

Ans: a (Trunk)Ref: IADVL, Vol. 1, 3rd ed. pg. 244Tuberculous gumma is a skin condition that results from haematogenous dissemination of mycobacteria from a primary focus, resulting in firm, nontender erythematous nodules that soften, ulcerate, and form sinuses.We could not find out a reference as to the commonest site of the TB gumma, but most texts show pictures of tuberculous gumma over the back of trunk. So we think that might be the answer.Scrofuloderma is a skin condition caused by tuberculous involvement of the skin by direct extension, usually from underlying tuberculous lymphadenitis.The most common site is the neck region. Tuberculids develop as a hypersensitivity response to a tuberculous foci in the body.Types of cutaneous TB1. Exogenous source Tuberculous chancre Lupus vulgaris2. Endogenous source Hematogenous/ lymphatic spreadLupus vulgarisAcute military tuberculosis of the skinTuberculous gummaContiguous spread/ auto inoculationScrofulodermaOrificial tuberculosis3. TuberculidsProbable tuberculidsLichen scrofulosorumPossible tuberculidsErythema induratumErythema nodosumFormer tuberculidsLichenoid tuberculidRosacea like tuberculidLupus miliaris disseminates facei