Lactose Intolerance Flashcards
What is lactose intolerance?
Inability to digest lactose due to shortage of lactase
Which sugar is primarily found in milk/dairy products?
Lactose
What is lactase?
Enzyme found in small intestine necessary for lactose digestion
Levels of lactase at birth, childhood, and adolescence?
High at birth, steadily declines during childhood and adolescence due to diet changing/no longer being as milk dependent
Is lactose intolerance the same as a milk allergy?
No, usually w allergy will have hives, respiratory involvement, angioedema, etc. rather than GI sx
How many people in the US have lactose intolerance?
Approximately 50 million
Who has higher prevalence of lactose intolerance?
Asian Americans, African Americans, Native Americans, Mexican Americans, Jewish Americans
Affects mostly those of non-European ancestry
Etiologies of lactose intolerance?
Acquired/genetically regulated, secondary to GI disease or surgery affecting proximal SI mucosa (Crohn’s, celiac, trauma)
Pathophysiology of lactose intolerance?
Malabsorbed lactose —> fermented by intestinal bacteria —> produces gas & organic acids, increase stool osmotic load —> diarrhea
Symptoms of lactose intolerance can vary depending on what?
Severity of lactase deficiency, amount of lactose intake
Clinical features of lactose intolerance?
Bloating, gas, diarrhea, cramping
It’s a red flag if someone presenting with lactose intolerance symptoms also presents with what? What is this concerning for?
Red flag: losing weight
Needs more extensive work up, concerning for cancer, celiac, etc.
Diagnostics for lactose intolerance?
Try lactose free diet
Oral ingestion of lactose/symptom survey
Hydrogen breath test
What is a hydrogen breath test for lactose intolerance?
Patient ingests 50gm of lactose mixed in water
Positive: rise in breath hydrogen of >20ppm within 90 min (indicates bacterial carbohydrate metabolism)
*lactose goes to bacteria, bacteria release gas which is transferred/exhaled by the lungs
Treatment goal of lactose intolerance?
Achieve patient comfort
Is complete intolerance of lactose rare or common?
Rare, many patients can tolerate small intake of lactose
How much milk can be spread out over the day and usually be well tolerated w no symptoms or need for lactase supplements in those w lactose intolerance?
8 oz per day spread out over the day
Treatment options for lactose intolerance?
Lactose free diet, milk pre-treated w lactase, lactase enzyme replacement (lactaid), consider calcium & Vit D for patients w very lactose restrictive diet
What is important to relay to patients who take lactaid?
It’s effects are very temporary/has a short window of being effective
Must take it just before eating, can take multiple if necessary (effects only last about 45 min - 1 hr)
