EPI is characterized by a deficiency of the above mentioned exocrine pancreatic enzymes, which results in an inability to digest food properly (maldigestion). Because pancreatic lipase accounts for up to 90% of fat digestion, maldigestion of fat is more profound in EPI than maldigestion of proteins and carbohydrates. Undigested fat, rather than being absorbed, is excreted in the feces. Major symptoms include steatorrhea and weight loss. Steatorrhea is the result of fat malabsorption and is characterized by pale, bulky, and malodorous stools. These stools often float on top of the toilet water with oily droplets and are difficult to flush. Weight loss and fatigue are common.
Other unabsorbed food substances release gaseous products such as hydrogen and methane. Flatulence often causes uncomfortable abdominal distention and cramps. Bleeding disorders are usually a consequence of vitamin K malabsorption and subsequent hypoprothrombinemia. Ecchymosis usually is the manifesting symptom, although melena and hematuria may occur on occasion.
Metabolic bone disease (vitamin D deficiency) and impaired night vision have been observed in patients with chronic pancreatitis because impaired enzyme secretion may be complicated by fat-soluble vitamin deficiencies. Vitamin A scarcity explains the poor night vision acuity, whereas prothrombin time may be prolonged because of malabsorption of vitamin K that yields poor coagulation, explaining the thigh bruise observed in the patient in this case.
EPI may also cause vitamin B12 deficiency because a decreased intestinal pH adversely affects the transfer of vitamin B12 from R protein to intrinsic factor. Patients with EPI may thus develop microcytic anemia due to iron deficiency or macrocytic anemia due to vitamin B12 or folate malabsorption.
In patients with cystic fibrosis, reduced chloride transport in the pancreas leads to reduced water content of secretions, precipitation of proteins, and plugging of ductules and acini, preventing the pancreatic enzymes from reaching the gut; autodigestion of the pancreas occasionally leads to pancreatitis.
Nesidioblastosis, or the more recent and accurate terms congenital hyperinsulinism or persistent hyperinsulinemic hypoglycemia of infancy, presents shortly after birth with symptoms of hypoglycemia (eg, hunger, jitteriness, lethargy, apnea, seizures). Older children, in addition to these symptoms, may also show diaphoresis, confusion, or unusual mood or behavior changes. Hypoglycemia is persistent, requiring frequent or continuous glucose infusions or feedings to maintain adequate blood glucose levels. Presenting symptoms of congenital hyperinsulinism reported in adults include confusion, headaches, dizziness, syncope, and loss of consciousness. The symptoms may be exacerbated by fasting and may improve after eating.
Zollinger-Ellison syndrome is caused by a non-beta islet cell gastrin-secreting tumor of the pancreas that stimulates the acid-secreting cells of the stomach to maximal activity, with consequent gastrointestinal mucosal ulceration. The primary tumor is usually located in the pancreas, but ectopic locations have also been described (eg, heart, ovary, gall bladder, liver, kidney). Seventy five percent of patients present with upper abdominal pain that mimics peptic ulcer disease.
This patient did not show symptoms that suggest any form of autoimmune disease.
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Cite this: Jaime Shalkow, Mayela E. García. A 15-Year-Old Girl With Steatorrhea Who Can’t See at Night - Medscape - Nov 13, 2019.