Ans. is 'b' i.e., Fibrinous Classification of pericarditisClinical classificationI. Acute pericarditis (<6 weeks)a) Fibrinousb) Effusive (serous or sanguineous)II. Subacute pericarditis (6 weeks to 6 months)a) Effusinve-constrictiveb) ConstrictiveIII) Chronic pericarditis (> 6 months)a) Constrictiveb) Effusivec) Adhesive (nonconstrictive)* Serous pericarditis is characteristically produced by non- infectious inflammatory diseases, including rheumatic fever, SLE, and scleroderma, as well as tumors and uremia. An infection in the tissues contiguous to the pericardium-- for example, a bacterial pleuritis--may incite sufficient irritation of the parietal pericardial serosa to cause a sterile serous effusion that can progress to serofibrinous pericarditis and ultimately to a frank suppurative reaction.* Fibrinous and serofibrinous pericarditis are the most frequent types ofpericarditis; these are composed of serous fluid variably admixed with a fibrinous exudate. Common causes include acute MI, postinfarction (Dressier) syndrome (an autoimmune response appearing days-weeks after an MI), uremia, chest radiation, rheumatic fever, SLE, and trauma. A fibrinous reaction also follows routine cardiac surgery.* Purulent or suppurative pericarditis reflects an active infection caused by microbial invasion of the pericardial space.* Hemorrhagic pericarditis has an exudate composed of blood mixed with a fibrinous or suppurative effusion; it is most commonly caused by the spread of a malignant neoplasm to the pericardial space.* Caseous pericarditis is, until proved otherwise, tuber- culous in origin; infrequently, fungal infections evoke a similar reaction.