FCAAIA Notes: By now, probably everyone with any interest in food allergy has heard about this study. To summarize, it shows that infants at risk of peanut allergy (history of severe atopic dermatitis and/or egg allergy) who had a negative skin test to peanut or who had a SMALL positive skin test but passed a peanut challenge were less much likely to become allergic to peanut if they ate peanut regularly until 5 years old. Children with LARGE skin tests or those who failed a peanut challenge in infancy were excluded.
About 15 years ago, the American Academy of Pediatrics (AAP) recommended peanut avoidance until 3 years old in hopes that the incidence of peanut allergy would decrease. It didn’t. In 2008, that recommendation was retracted because there was no evidence that delaying introduction changed the risk of peanut allergy. Now, we have powerful evidence that early introduction decreases risk in some children.
There are important caveats, however. Continue reading
FCAAIA Notes: Fructose is a sugar found in its natural form in fruits and vegetables. So, is this study saying women shouldn’t eat a lot of fruit during pregnancy? No, not at all. The title and the study from which it is derived are a perfect example of why we need to read all the information and not jump to conclusions because of a headline.
Fructose is commonly added to soft drinks and juice to sweeten the beverage. In truth, it was excessive ingestion of fructose infused processed refreshments Continue reading
FCAAIA Notes: With the recent exciting research about early introduction of peanut to an infant’s diet, I thought it apropos to post a recent “state-of-the-art” review of peanut allergy. I put that phrase in quotes because things change fast in medicine. If you have read this far down in my blog, you already read about the LEAP study. Now, read this full article and compare Continue reading
FCAAIA Notes: The relationship between obesity and asthma is complex for a variety of reasons. Many obese patients are short of breath merely because their chest wall is less compliant and does not expand with inhalation as easily as in patients of normal weight. Often, their shortness of breath is misdiagnosed and treated as asthma. Obese patients have often less well physically conditioned so have exercise induced symptoms unrelated to asthma. Finally, obesity predisposes to GE reflux, a common cause of cough and common trigger to asthma symptoms. So, weight loss can lead to symptom improvement even if the symptoms are not asthmatic.
Of course, obesity is a risk for numerous other chronic, dangerous and potentially life threatening problems. It doesn’t matter if you have asthma or not. If you are obese, talk to your primary care physician to discuss weight loss strategies. Continue reading
FCAAIA Notes: There is a lot of news about oral food desensitization, or oral immunotherapy (OIT). Of course the reported news is always about the most exciting and promising advances. But, these reports need to be vetted carefully, as not all that glitters is gold. There is promise in the future of peanut OIT, but the procedure has a relatively high rate (5-10%) of reactions including anaphylaxis. Even in this exciting study from the University of North Carolina, only 10.7% of patients who were on high doses of peanut every day (the equivalent more than 2 tablespoons of peanut butter) could tolerate it after stopping their daily doses for an extended time.
We can only conclude that peanut allergy is not curable (yet). Maybe Continue reading
FCAAIA Notes: Asthma and allergies run in families, but do not exclusively run in families. We frequently hear parents’ surprise that their children have asthma or allergies because no one in the family does. For round numbers, if neither parent has allergies (is atopic), their children will have a 15-20% chance of having allergies. The risk roughly doubles for each affected parent so that if both parents are atopic, their children each have about a 50-60% chance of atopy. There ahs been the suggestion over the years that maternal atopy might contribute to risk greater than paternal history.
This study indicates that a parental history of atopy not only contributes to risk, but contributes to Continue reading
FCAAIA Notes: The best data on probiotics and allergic disease probably apply to atopic dermatitis and food allergy in infancy. Unfortunately, while there are some studies indicating some benefits, none have been so conclusive that it is a recommendation we routinely make. Some good news is that probiotics and prebiotics are unlikely to be harmful to mother, fetus, or infant (as far as we know!). Furthermore, not all studies use the same probiotics, so we cannot recommend a particular species.
I think the data on probiotic use to prevent allergic disease is nicely summarized by the authors and appears at the end of this article: “If probiotics are used in infants, Continue reading
FCAAIA Notes: Oral food desensitization (oral immunotherapy, OIT) is not without risk. In fact 5-10% of patients undergoing food OIT experience significant reactions, including anaphylaxis in some cases. Asthma is a risk factor for OIT reaction. I don’t see this as a real surprise, as asthma (especially poorly controlled asthma) is a risk factor for more severe food allergy reactions in general. Peanut OIT has received the most attention recently. One cannot necessarily extrapolate the findings for one food to another, but we have no reason to suspect risk factors vary from one food to another.
Food OIT is still a research tool and should not be undertaken at home. Continue reading
FCAAIA Notes: The association between chronic diseases (yes, asthma IS a chronic disease) and psychological conditions including depression was well established years ago. The proverbial “chicken-egg” question has always been part of the equation. Things seems to work both ways: Patients with depression are more likely to have chronic disease, complications of their disease, and a greater impact on their quality of life by their disease. Conversely, patients with chronic disease (especially poorly controlled) are more likely to become depressed.
So, if you have poorly controlled asthma take care of your mental as well as your physical health. Continue reading
FCAAIA Notes: It’s not always so easy to tell if some one had a true reaction to a food ingestion. The double-blind, placebo-controlled food challenge, in which neither doctor nor patient know if the food or an innocuous substance is ingested, is the gold-standard for the diagnosis of food allergy. Objective, measurable reactions are easy to identify. But, what about subjective symptoms such as itch, fatigue, abdominal pain without hives, vomiting etc.? Are they a result of the food itself or the suggestibility that the food will cause a reaction (“nocebo effect”, in which if the patient thinks something bad will happen, he is more likely to complain about a reaction)?
This study identified how experts can disagree Continue reading