Metabolic disorders and food allergies Flashcards
How is a food allergy different than an intolerance
an allergy is an adverse reaction to food ingestion mediated by IgE
Intolerance is difficulty digesting or metabolizing a food
Food allergy is the main reason for
Anaphylaxis presenting to the ER
What are symptoms of a food intolerance
Gas, bloating, abdominal pain, and diarrhea
What are Sx of a food allergy
Immediate* pruritis, urticaria, flushing, swelling of lips, face, throat, nausea, vomiting, cramping, diarrhea, wheezing, light headed, hypotension, syncope
How do you diagnose a food allergy
Take an amazing history! have them keep a food journal
They can do a 2 week trial elimination
What history is important when suspecting food allergy
Frequency of food eaten Quantity eaten Ingredients How the food is prepared GI vs Derm vs Respiratory Sx Time in between exposures
What labs can you get if you suspect a food allergy
IgE test (skin prick test or IgE immunoassay) but, think about the pre-test probability; all the things you could find that you now need to work up and treat that weren't even Sx
How do you treat a food allergy
Epinephrine auto-injector (epi pen)- give GOOD instructions
Food avoidance
Allergist referral
What is lactose intolerance
Intolerance to lactose containing food
MC in black, hispanic, asian, native american
Prevalence increases w/ age (not common <6 y/o)
What normally happens to lactose in the body
Lactase is found on microvilli of intestinal membrane.
It breaks down lactose to glucose and galactose
G&G are absorbed by the small intestine
Lactose that isnt absorbed goes into colon to be converted to fatty acid and hydrogen gas by colon bacteria
How does lactose intolerance occur
If you are missing lactase, you have a lactose malabsorption
All the lactose you eat goes into the small intestine and is converted to fatty acid and hydrogen gas
Primary vs secondary causes of lactose intolerance are
Primary: race, development, congenital deficiency
Secondary: Bacteria overgrowth, infectious enteritis, mucosal injury (celiac, IBD)
How does lactose intolerance present
Abdominal pain Bloating flatulence diarrhea Borborygmi (really loud BS) Sx are affected by diet and vary in severity
How do you diagnose lactose intolerance
Sx after lactose ingestion that resolve w/ avoidance
Lactose hydrogen breath test at baseline and q30 min x 3 hours
how do you treat lactose intolerance
Lactose free diet
Lactase enzyme helps a bit
Monitor calcium and vitamin D