This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Mycobacterial Infections, Subject name: Dental
False about erythema nodosum? 
Select and explain. 
A. Considered a hypersensitivity reaction, B. Is a lobular panniculitis, C. Overlying skin is red, smooth and shiny, D. Can be seen in TB
B: Is a lobular panniculitis
Answer: B: Is a lobular panniculitis 
Explanation: 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 Crohn's disease> Ulcerative colitis SLE, RA, Reiter's Syndrome Sweet Syndrome Pregnancy Malignancy Disease Description Group Affected/Epidemiologic 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