Inflammation of a serous membrane, such as the lining of the thoracic cavity (pleura).
An inflammation of a serous membrane, such as the pleura, pericardium, or peritoneum. Serositis is one of the cardinal findings in connective tissue diseases like systemic lupus erythematosus.
The inflammation of a serosal membrane is known as serositis. When two or more serosal membranes are inflamed simultaneously, it is referred to as polyserositis.