Peritonitis is an inflammation of the peritoneum, the tissue that lines the inner wall of the abdomen and covers and supports most of your abdominal organs. Peritonitis is usually caused by infection from bacteria or fungi.
Left untreated, peritonitis can rapidly spread into the blood (sepsis) and to other organs, resulting in multiple organ failure and death. So if you develop any of the symptoms of peritonitis -- the most common of which is severe abdominal pain -- it's essential to seek prompt medical evaluation and treatment that can prevent potentially fatal complications.
The spleen is a delicate, fist-sized organ under your left rib cage near your stomach. It contains special white blood cells that destroy bacteria and help your body fight infections. The spleen also makes red blood cells and helps remove, or filter, old ones from the body's circulation.
A layer of tissue entirely covers the spleen in a capsule-like fashion, except where veins and arteries enter the organ. This tissue, called the splenic capsule, helps protect the spleen from direct injury.
The two main types of peritonitis are primary spontaneous peritonitis, an infection that develops in the peritoneum; and secondary peritonitis, which usually develops when an injury or infection in the abdominal cavity allows infectious organisms into the peritoneum. Both types of peritonitis are life-threatening. The death rate from peritonitis depends on many factors, but can be as high as 40% in those who also have cirrhosis. As many as 10% may die from secondary peritonitis.
The most common risk factors for primary spontaneous peritonitis include:
Liver disease with cirrhosis. Such disease often causes a buildup of abdominal fluid (ascites) that can become infected.
Kidney failure getting peritoneal dialysis. This technique, which involves the implantation of a catheter into the peritoneum, is used to remove waste products in the blood of people with kidney failure. It's linked to a higher risk of peritonitis due to accidental contamination of the peritoneum by way of the catheter.