(See also Overview of Pancreatitis.)
Chronic pancreatitis is long-standing inflammation of the pancreas that results in irreversible deterioration of the structure and function of the pancreas.
Excessive alcohol consumption and cigarette smoking are two major causes of chronic pancreatitis.
Abdominal pain may be persistent or come and go.
The diagnosis is based on the symptoms, a history of recurring acute pancreatitis and alcohol abuse, imaging tests, and pancreatic function tests.
Treatment involves avoiding alcohol and cigarettes, modifying the diet, taking pancreatic enzyme supplements, and measures to relieve the pain.
The pancreas is an organ in the upper abdomen that produces the hormone insulin and secretes pancreatic fluid through the pancreatic duct into the first part of the small intestine (duodenum). This pancreatic fluid contains digestive enzymes that help digest food. In acute pancreatitis, inflammation develops quickly and subsides within a few days to a few weeks. In chronic pancreatitis, inflammation is progressive and long-standing, which causes permanent damage to the pancreas. As chronic pancreatitis progresses, cells that secrete the digestive enzymes in the pancreatic fluid are slowly destroyed over time.
In the United States, about half of the cases of chronic pancreatitis are due to alcoholism. People who smoke cigarettes also are at increased risk of developing chronic pancreatitis.
Less common causes of chronic pancreatitis include genetic disorders, such as cystic fibrosis, hereditary pancreatitis, or autoimmune pancreatitis. Rarely, an attack of severe acute pancreatitis causes permanent scarring of the pancreas that leads to chronic pancreatitis. In some people, chronic pancreatitis develops when the pancreatic duct is blocked (obstructed) by stones.
Some cases of chronic pancreatitis have no clear cause (are idiopathic). In tropical countries (for example, India, Indonesia, and Nigeria), chronic pancreatitis of unknown cause occurs among children and young adults (called tropical pancreatitis).
Abdominal pain is the main symptom of chronic pancreatitis. The upper abdominal pain may vary in intensity, and flare-ups (bouts or attacks) may last for many hours or several days. Later on in the illness, pain tends to become constant. The pain is usually worse after meals and may be lessened by sitting upright or leaning forward.
As chronic pancreatitis progresses and the cells that secrete the digestive enzymes are destroyed, the abdominal pain may stop.
Pancreatic insufficiency is the other main manifestation of chronic pancreatitis. Pancreatic insufficiency is a decrease in the amount of digestive enzymes in pancreatic fluid. As the amount of digestive enzymes decreases, food is inadequately broken down. Food that is inadequately broken down is not absorbed properly (malabsorption), and the person may produce bulky, unusually foul-smelling, greasy stools (steatorrhea). The stool is light-colored and may even contain oil droplets. Undigested muscle fibers may also be found in the feces. The inadequate absorption of food also leads to undernutrition and weight loss.
A fluid collection called a pancreatic pseudocyst can develop. Pseudocysts can bleed or rupture and ones that expand may cause pain or block the duodenum or bile ducts.
Eventually, the cells of the pancreas that secrete insulin may be destroyed, gradually leading to diabetes.
Patients with chronic pancreatitis are at increased risk of pancreatic cancer.
A doctor suspects chronic pancreatitis because of a person’s symptoms and history of acute pancreatitis flare-ups or alcohol abuse. Blood tests are less useful in diagnosing chronic pancreatitis than in diagnosing acute pancreatitis, but they may indicate elevated levels of amylase and lipase (two enzymes produced by the pancreas). Also, blood tests can be used to check the level of sugar (glucose) in the blood, which may be elevated.
X-rays of the abdomen may be done to look for calcium deposits in the pancreas, which are present in some people with chronic pancreatitis.
CT of the abdomen may be done to show changes of chronic pancreatitis and to look for complications, such as a pseudocyst.
Many doctors now do a special MRI test called magnetic resonance cholangiopancreatography (MRCP). MRCP shows the bile and pancreatic ducts more clearly than does CT.
Endoscopic retrograde cholangiopancreatography (ERCP) allows doctors to view the bile duct and pancreatic duct. This test is rarely used for the diagnosis of chronic pancreatitis, but doctors may do it if a certain treatment for the pancreatic duct is needed, such as placing a tube (stent) through a blockage or removing a stone in the duct.
Understanding Endoscopic Retrograde Cholangiopancreatography
Endoscopic ultrasonography (passage of a flexible viewing tube with an ultrasound probe attached to it through the mouth into the stomach and the first segment of the small intestine) is another test that helps detect abnormalities in the pancreas and pancreatic duct.
Because people with chronic pancreatitis are at increased risk of pancreatic cancer, any worsening of symptoms or narrowing of the pancreatic duct makes doctors suspect cancer. In such cases, a doctor is likely to do blood tests, a magnetic resonance imaging (MRI) scan, a computed tomography (CT) scan, or endoscopic ultrasonography.
For chronic pancreatitis, doctors may also do tests of the pancreas to see how it is functioning. These tests help doctors determine whether there is pancreatic insufficiency that can cause malabsorption. Stool may be checked for levels of fat or a digestive enzyme such as elastase. Low levels of elastase indicate pancreatic insufficiency.
The prognosis for chronic pancreatitis varies and is relatively poor.
Even if alcohol is not the cause, all people with chronic pancreatitis should avoid drinking alcohol and stop smoking.
Pain control is the most challenging part of managing chronic pancreatitis, and treatments are focused on reducing pain and slowing disease progression. Eating four or five meals a day consisting of food low in fat may reduce secretion of pancreatic enzymes and reduce pain.
Opioid analgesics are sometimes needed to relieve the pain. Too often, pain relief measures do not relieve the pain, requiring increased amounts of opioids, which may put the person at risk of addiction. Doctors may recommend additional pain drugs, such as tricyclic antidepressants, gabapentin, pregabalin, and selective serotonin reuptake inhibitors (SSRIs), and prescribe them either alone or in combination with opioids to manage chronic pain, but results vary. Drug treatment of pain in chronic pancreatitis is often unsatisfactory.
Sometimes doctors may use an endoscope (a flexible viewing tube) to carry out treatment. Endoscopic treatment with endoscopic retrograde cholangiopancreatography (ERCP) may be used to drain a duct that is blocked by scarring (stricture), stones, or both. This procedure may provide pain relief.
Lithotripsy (a procedure that involves the use of shock waves to break up stones) may be used to treat stones that are large or stuck in the pancreatic duct.
Surgical treatment may be an option if the pancreatic ducts are dilated or if there is an inflammatory mass in one region of the pancreas. For instance, when the pancreatic duct is dilated, creating a bypass from the pancreas to the small intestine relieves the pain in about 70 to 80% of people. When the duct is not dilated, part of the pancreas may have to be removed. Removing part of the pancreas means that cells that produce insulin are removed as well, and diabetes may develop. Doctors reserve surgical treatment for people who have stopped using alcohol and who can manage any diabetes that develops.
Sometimes a pancreatic pseudocyst can cause pain as it expands and may have to be drained (decompressed) endoscopically, surgically, or through the overlying skin.
Pancreatic enzyme supplementation may reduce chronic pain by reducing the secretion of pancreatic enzymes. Although enzyme therapy is often tried because it is safe and has few side effects, it may not provide substantial pain relief.
For people who have pancreatic insufficiency, taking tablets or capsules of pancreatic enzyme extracts with meals can make the stool less greasy and improve food absorption, but these problems are rarely eliminated. The supplements should be taken with meals. Doctors sometimes recommend people take a histamine-2 (H2) blocker or a proton pump inhibitor (drugs that reduce or prevent the production of stomach acid) with the pancreatic enzyme supplements. With pancreatic enzyme treatment, the person usually gains some weight, has fewer daily bowel movements, has no more oil droplets in the stool, and generally feels better. If these measures are ineffective, the person can try further decreasing fat intake. Supplements of the fat-soluble vitamins (A, D, E, and K) also may be needed.
(See also Treatment of Diabetes.)
Hypoglycemic drugs taken by mouth rarely help treat diabetes caused by chronic pancreatitis. Insulin is generally needed but can cause a problem, because affected people also have decreased levels of glucagon, which is a hormone that acts to balance the effects of insulin. An excess of insulin in the bloodstream causes low glucose (sugar) levels in the blood, which can result in a hypoglycemic coma (see Symptoms of Hypoglycemia).