<prompt> Erythema multiforme ?StaphylococcusTBHSVEBV  <response>: Ans. is c i.e., HSV Idiopathic erythema multiforme is the most common cause of EM. o Herpes simplex is the most impoant infectious cause of EM. Causes of Erythema multiforme Idiopathic --- Most common cause Viral -- HSV most impoant HBV, Mumps, Adenovirus o Bacteria -9 Streptococci, tuberculosis Fungal -- Coccidioidomycosis, Histoplasmosis. Drugs --- Antibiotics Sulphonamide, Phenytoin, NSAIDS. o Autoimmune disease -- SLE, thyroiditis, RA Others -- Sarcoidosis, Pregnancy, Malignancy 