Exocrine pancreatic insufficiency occurs in chronic pancreatitis, cystic fibrosis, autoimmune disorders such as Crohn’s disease and systemic lupus erythematosis and patients that have had parts of their stomach or pancreas removed surgically, including those with pancreatic cancer.
The most common cause of chronic pancreatitis is alcohol. Typically, a daily intake of 150 grams per day or more is required. In most cases, there is a long history of alcohol consumption, either on a daily basis or multiple times a week. It typically occurs in 10-15% of such heavy drinkers, and it is unclear why it occurs in some and not others.
Other less common causes of chronic pancreatitis are hereditary pancreatitis, obstructive chronic pancreatitis, hyperparathyroidism, hypertriglyceridemia and prior abdominal radiation. About 20-30% of cases of chronic pancreatitis will be idiopathic in nature, where no known cause is identified. It is unclear how chronic pancreatitis occurs from these conditions, but theories include blockage of the pancreatic duct resulting in pancreatic duct stones, which lead to excessive inflammation in the area of the duct.
Cystic fibrosis is a hereditary condition occurring as a result of a genetic defect. The disease was typically limited to infants and children, and is usually diagnosed in the first several years of life. In 3% of cases, the diagnosis is not made until after the age of 18. Patients have pulmonary symptoms of cough and unexplained lung disease, as well as pancreatic insufficiency. The diagnosis of cystic fibrosis is made by finding abnormal sweat electrolytes; with elevations of sodium and chloride sweat concentration in 99% of patients.
There are certain autoimmune disorders, in which the body attacks itself, that can disrupt the pancreas, resulting in an autoimmune pancreatitis. Two diseases that can be associated with this condition are Crohn’s disease, an inflammatory disorder of the colon and small intestine, and systemic lupus erythematosis, a vasculitis, that can attack the pancreas as well. If a significant portion of the pancreas is affected, the result is exocrine pancreatic insufficiency.
Patients that have surgical removal of part of the pancreas, resulting in a significant decrease in pancreatic enzyme activity can develop pancreatic exocrine insufficiency. Additionally, patients who have had partial stomach resections can develop pancreatic exocrine insufficiency as well. Patients with Zollinger-Ellison syndrome, the production of excessive amounts of gastrin, develop multiple gastric and duodenal ulcers and can have exocrine pancreatic insufficiency as well. Celiac disease has been associated with low levels of fecal elastase which is consistent with exocrine pancreatic insufficiency.
Finally, there are multiple rare hereditary disorders of the exocrine pancreas, and they include Shwachman’s syndrome, Pearson’s marrow-pancreas syndrome, Johanson-Blizzard syndrome and isolated enzyme deficiencies.