<prompt> Bazin;s disease is also called asErythema nodosumErythema induratumErythema multiformeErythema marginatum  <response>: Erythema induratumnodular vasculitis Epidemiology :- Women primarily; 30-40 yrs. Pathogenesis :- May be aw tuberculosis erythema induratum of Bazin or idiopathic nodular vasculitis Tissue culture for mycobacteria usually negative. PCR tests for M. tuberculosis more sensitive. Likely type IV cell-mediated response to antigen . Clinical features :- Tender, recurrent red-purple nodules and plaques on calves most commonly. May ulcerate, drain and scar. Ref:- Review of Dermatology by Alikhan; pg num:-190 