Tropical chronic pancreatitis
Tropical chronic pancreatitis (TCP) is a type of chronic calcific non-alcoholic pancreatitis that is found almost entirely in developing countries in the tropics. People with TCP typically develop abdominal pain, steatorrhoea (abnormal excretion of fat due to poor absorption), and diabetes. Tropical chronic pancreatitis usually presents before the age of 40 and men are more likely to be affected than women.
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Definition & Facts
Tropical chronic pancreatitis, a precursor to fibrocalculous pancreatic diabetes (FCPD), is a form of chronic pancreatitis found in developing tropical nations with several features that set it apart from other types of chronic pancreatitis. Those with TCP carry a high risk of developing pancreatic carcinoma.
Diabetes is also a hallmark of the disease and it may take up to a decade to appear after initial symptoms of the disease. The disease was first described in 1959 in Indonesia, but it has been reported in Southeast Asia, South America, and Africa. It has the highest prevalence in South India.
Symptoms & Complaints
There may also be emaciation and a distended abdomen. About 20 percent of patients have steatorrhoea, which is a higher-than-normal excretion of fat in the feces due to poor fat absorption in the intestine. The proportion of people affected by steatorrhoea increases as dietary fat content increases.
Diabetes typically develops up to ten years after the first presentation of abdominal pain. About 80 percent of patients eventually require insulin. TCP also results in pancreatic fibrosis which is tissue damage that results in shrinkage of the pancreas combined with dilation of the pancreatic ducts and the formation of pancreatic stones.
TCP causes a significantly increased risk of pancreatic carcinoma with research suggesting the rate may be as high or higher than other types of chronic pancreatitis. After the disease progresses to FCPD with diabetes, the median survival rate is around 25 years.
Causes
The exact cause of tropical chronic pancreatitis is unknown, although it's believed that malnutrition and possibly toxin exposure are factors as the disease usually develops in areas of poverty and malnutrition. It has been proposed that cassava consumption is related to the development of TCP as the disease is common in parts of the world in which the crop is consumed. This root crop, which originates in South America, grows in poor soil conditions but contains thiocyanates that are not fully removed with crude extraction methods.
There are also genetic factors associated with tropical chronic pancreatitis. There is an association between FCPD and the HLA gene complex that encodes proteins responsible for regulating the immune system, particularly an increase in the transmission of one HLA protein and a decrease in the transmission of another HLA protein.
There is also a reported association with the trypsin inhibitor gene, SPINK1 gene that inhibits premature activation of trypsinogen in the pancreas. This gene is also associated with other types of chronic pancreatitis. Between 20 percent and 55 percent of patients are found to have a mutation of the SPINK1 gene with the N34S mutation being the most common. Men are affected about two to three times more often than women.
Diagnosis & Tests
Diagnosis of tropical chronic pancreatitis is usually made in young people before the age of 40 based on a clinical physical examination. Diagnosis may be based on clinical presentation of abdominal pain, malabsorption of fat, and diabetes.
The hallmark of TCP that aids in diagnosis is dilation of the pancreatic ducts accompanied with large stone formation. Both duct dilation and stone formation may be seen on an abdominal X-ray. Duct dilation can also be diagnosed through endoscopic retrograde cholangiopancreatography, endoscopic ultrasound, or a computed tomography (CT) scan. A physician may also order tests of exocrine pancreatic function tests, although these tests are only to support a diagnosis.
An important criteria for diagnosing tropical chronic pancreatitis is ruling out alcoholic pancreatitis. Alcohol abuse is the leading cause of chronic pancreatitis in most areas of the world, although it is rarely prevalent in areas in which TCP presents. People diagnosed with alcoholic pancreatitis are usually older and are less likely to have pancreatic stones, which tend to be smaller when they do present.
Treatment & Therapy
Treating tropical chronic pancreatitis requires addressing malabsorption, pancreatic duct dilation, and diabetes. About 80 percent of people with FCPD require insulin therapy, but about 20 percent of people have diabetes that can be effectively controlled with dietary changes and oral medication.
Surgical intervention are sometimes needed for drainage of the pancreatic duct or pancreatic resection, a procedure in which some of the pancreas, gallbladder, and bile ducts are removed. Malabsorption can be addressed with oral pancreatic enzymes.
One of the most difficult symptoms of TCP to manage is abdominal pain. While some patients report improved pain in the long-term, many live for decades with abdominal pain that is intermittent or persistent and severe. Abstaining from alcohol and quitting smoking to prevent further damage to the pancreas can avoid aggravating pain while non-narcotic analgesics like nonsteroidal anti-inflammatory drugs may help manage the pain.
Obstruction of the main pancreatic duct is believed to cause much of the pain of the condition so treating obstructions with surgical duct decompression therapy or endoscopic surgery can offer relief.
Prevention & Prophylaxis
Alcohol consumption and smoking are also associated with chronic pancreatitis and may increase the risk of TCP. Avoiding these risk factors may reduce the risk of developing tropical chronic pancreatitis as it's believed to be caused by a combination of genetic and environmental factors.