DDSEP® 8 Quick Quiz

January 2017 Quiz 1

Q1: A 60-year-old woman complains of progressive weakness and fatigue and has a stumbling gait. She has three soft, loose stools each day, which has been a stable pattern since her gastric bypass (standard bariatric gastrojejunostomy) 10 years ago. Her physical exam is notable only for some pallor of the mucosal membranes, diminished touch sensation of the extremities, and an abnormal gait with impaired tandem walking and balance. There was no glossitis or rash. Stool testing was negative for occult blood. Initial lab tests revealed a moderate microcytic anemia, normal electrolytes, renal function, and liver tests. Iron supplementation was provided for 3 months, after which the microcytic anemia was noted to have worsened despite normal iron values on follow-up testing.

January 2017 Quiz 1 - A deficiency in which of the following is most likely?

Riboflavin

Copper

Zinc

Iron

Vitamin B12

Q1: Answer: B

Rationale: Although copper deficiency could be a complication of extensive enteropathy from conditions such as Crohn’s disease, celiac disease, short gut syndrome, or HIV enteropathy, it is more commonly recognized as a complication of gastric bypass surgeries. Copper absorption is thought to be primarily in the stomach and proximal small intestine. Copper is partially excreted in the bile, and patients with chronic external biliary drains may also develop copper deficiency. Deficiency in copper has also been recognized as a complication of zinc toxicity from deliberate chronic ingestion of zinc or unintentional industrial overexposure to zinc, and can also be a complication of chronic total parenteral nutrition in the absence of routine micronutrient supplementation. Complaints of muscle weakness and gait disturbance with copper deficiency are secondary to a myeloneuropathy similar to vitamin B12 deficiency. Copper deficiency may present as a microcytic anemia and neutropenia and, in advanced cases, may mimic a myelodysplastic syndrome. The microcytic anemia of copper deficiency is worsened by iron supplementation, which can reduce copper absorption.

Riboflavin deficiency may manifest with photophobia, burning mouth sensation, and glossitis. Zinc deficiency may manifest as diarrhea, altered taste sensation (dysgeusia), night blindness, and a characteristic acrodermatitis. Iron deficiency principally manifests as a microcytic anemia. Vitamin B12 deficiency is associated with gastric bypass surgery, as well as resection of the ileum, and may result in myeloneuropathy, but characteristically is associated with a megaloblastic, macrocytic anemia.

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