<prompt> False about erythema nodosum?Considered a hypersensitivity reactionIs a lobular panniculitisOverlying skin is red, smooth and shinyCan be seen in TB  <response>: Erythema nodosum EN is a cutaneous reactive septal panniculitis with no vasculitis. Causes: Drugs like OCPs, sulphonamides and Penicillin. Infections - Gp A b haemolytic Streptococcus infection, Brucella, Toxoplasmosis, CMV, E.coli etc. Tuberculosis Sarcoidosis Crohns disease Ulcerative colitis SLE, RA, Reiters Syndrome Sweet Syndrome Pregnancy Malignancy Disease Description Group AffectedEpidemiologic Factors Clinical Syndrome Erythema nodosum septal panniculitis - Large, violaceous, nonulcerative, subcutaneous nodules; - exquisitely tender; - usually on lower legs but also on upper extremities. - self limiting following drug withdrawal and usually resolves within 2-4 weeks More common in females 15-30 years old Ahralgias 50; features vary with associated condition 