Zinc or Swim: Unexpected Case of Zinc Deficiency

Abstract

Background: Zinc deficiency is estimated to affect over two billion people in the developing world. About 10% of the U.S. population intakes less than half the advised amount of zinc, and is at risk for zinc deficiency. It can be inherited, acquired, or secondary to poor dietary intake and altered metabolism. In this case report, we present an 86-year-old male with pancreatic cancer on palliative chemotherapy, presenting with multiple episodes of non-bloody diarrhea related to severe zinc deficiency. Case report: An 86-year-old male diagnosed two months earlier with pancreatic cancer undergoing palliative chemotherapy presented with multiple episodes of non-bloody diarrhea, despite use of antidiarrheal medications. Laboratory studies revealed severe neutropenia, bandemia, anemia, hypomagnesemia, and hypophosphatemia. CT abdomen/pelvis showed several thick-walled loops of small bowel in the pelvis and thickening of the wall of the descending colon. Initial management included fluid and electrolyte resuscitation, neutropenic precautions, and empiric antibiotics for concern that symptoms were secondary to chemotherapy versus infection or malabsorption. Stool cultures, ova and parasites, Clostridium difficile, and blood cultures were evaluated. However, despite treatment for two weeks, negative cultures, and trial of loperamide, the patient's diarrhea persisted, and he continued to deteriorate clinically. He began to have dysguesia and alopecia. At that point, a plasma zinc level was checked and found to be low at 0.42 (normal 0.66 to 1.1). The patient had a nutritional evaluation, and was started on zinc supplementation with resolution of his diarrhea in a few days and marked clinical improvement. Discussion: The prevalence of zinc deficiency worldwide is estimated at more than 20%. The majority of cases of zinc deficiency have been described in children, and we believe that our case is the first to highlight this disorder in adults. Zinc deficiency manifests in a variety of different ways, including acrodermatitis enteropathica, depressed immunity and spermatogenesis, dysguesia, diarrhea, and night blindness. It is noted that not only can zinc deficiency cause diarrhea, but can also be secondary to severe diarrhea, resulting in a continuous cycle of deficiency and malabsorption. Many studies have shown significant benefit with zinc supplementation in high-risk patients. This case illustrates the importance of considering zinc deficiency in patients with persistent diarrhea of unclear etiology in order to provide optimal management and reduce morbidity.