The topic of food allergies is murky and confusing. Many reactions reported as allergy to a food product are really mere intolerance, over-eating or other factors. True food allergies are thought to occur in 8 percent of children under age 5 and only 3 to 4 percent of adults. The frequency of allergies does not vary much around the world, while both genders are equally affected.
True food allergies can cause reactions that differ from mild digestive issues, rash, hives or difficulty breathing. Anaphylaxis is the most severe form of allergic reaction, with onset within 20 minutes of ingestion that progresses rapidly, resulting in hives, shortness of breath, rapid pulse and even death if not immediately treated. Although estimates of life-threatening reactions vary widely, it comprises only a small number of the overall allergic reactions to food. True food allergies usually occur within 2 hours or less after ingesting the food. Onset of swelling or tingling around the throat, lips, face or hives and itching are early signs. It can progress to dizziness, nausea, vomiting or difficulty breathing. Which symptoms and how rapidly it progresses may be different in one person to the next.
Food intolerance is only sensitivity to a food that is driven by a different physiologic mechanism that causes much milder symptoms and does not lead to more severe reactions. A good example of this is lactose intolerance, or sensitivity to milk and dairy products. Due to an enzyme deficiency, it often results in abdominal gas, discomfort, cramping and diarrhea. It is a lot more common and vastly different than a true food allergy.
The most common food allergies are eggs, milk, peanuts, tree nuts (i.e. walnuts, pecans) wheat, and shellfish (shrimp, lobster, crab, clams). Regular fish and chocolate are much less common allergens than anecdotes suggest.
Food intolerance can be confused with an allergy. Only a small amount of a food can trigger a severe allergic reaction. Food intolerance, food poisoning, stress, a virus, medications, food additives (preservatives, coloring) can all produce similar but milder symptoms, particularly intestinal problems. So it can be confusing at times to ascertain what the origin of the reaction may be.
A family history of food allergies, asthma or eczema increases the risk of true food allergies. Allergic individuals may cross react between certain allergens. Some of those sensitivities can extend between dissimilar items that may not be obvious. Consulting your healthcare provider, an exam and possible testing may be able to provide peace of mind, appropriate treatment and identify what to avoid in the future.
The most important aspect of managing food allergies is avoidance. Unfortunately there is no specific treatment. Antihistamines are still the first line of defense in both children and adults at the onset of a food allergy. If severe, prompt medical attention may be needed. Food allergies in children often change over time. The onset is most common in the first few years of life but can occur at any age. Allergies do get better in some children as they get older. Research shows there is no relationship between allergies and when new foods are introduced after 6 months of age.
Variation in personal experience seems to be the rule. Family and personal history of allergies are stronger predictors of future course. The severity of a past reaction cannot predict the severity of a future reaction.
When in doubt about food sensitivities or allergies, simply avoid it! Consult your healthcare provider to help with any confusion.
– Dr. Bruce Kaler