Here is an article that my friend (who is a family doctor) sent to my BiL who has a 3 y.o. that has had bad eczema since she was a few months old:
Dear Clinician, Here is the information you requested (sourced from Journal Watch).
Making Sense of Food Allergies
Food allergy management is hampered by overdiagnosis and lack of consensus on diagnostic criteria.
Food allergy affects more than 1% to 2%, but less than 10%, of the U.S. population, yet this potentially life-threatening condition is poorly understood. In an NIH-sponsored review of food allergy studies from 1988 to 2009, the authors note their analysis was hampered by lack of high-quality studies and by lack of consensus on the definition and diagnosis of food allergy. They make the following observations:
The general perception that food allergy prevalence is increasing has not been established in well-designed studies.
Skin-prick testing and in vitro specific IgE (sIgE) determination are both sensitive, but not specific: Roughly 50% of patients with a questionable history and positive test result will not have true food allergy. Food challenges are the gold standard but are cumbersome and potentially dangerous.
Specific food immunotherapy looks promising, but studies are still under way to distinguish between tolerance (long-term clinical nonreactivity) and desensitization (temporary ability to tolerate food). Anti-IgE therapy appears to confer protection against peanut reactions in some patients.
Probiotics plus either breast-feeding or hypoallergenic formula for high-risk infants may slow or prevent the onset of allergic disease. Evidence is conflicting on the effect of allergen-free diets in pregnant and lactating women.
Comment: This review highlights the difficulties in diagnosing and treating food allergy. Inappropriately diagnosing food allergy restricts diets, causes anxiety and social challenges, and trivializes a life-threatening condition. Because of the potential for life-threatening events, patients with suspected IgE-mediated food allergy should undergo testing with either skin-prick or sIgE. Patients who have positive test results but do not have a convincing history should be considered for food challenge. Primary care physicians who are not comfortable with this testing should refer patients to allergists. Avoidance and self-injectable epinephrine are the current standard of care. We can hope that specific food immunotherapy will soon be a viable option.
— David J. Amrol, MD
David J. Amrol, MD, is an Assistant Professor of Clinical Internal Medicine and Director of the Division of Allergy and Immunology at the University of South Carolina School of Medicine in Columbia.
Published in Journal Watch General Medicine May 25, 2010
Here is my friend's translation:
True allergies (IgE mediated) remain very scary and potentially lethal; other (and non-IgE mediated) allergies are just more of a hassle. IgE mediated allergies can cause swelling of soft tissues, such as the mouth, lips, and throat, which can then block the airway--hence they can be deadly quickly. While it's easiest (in theory) to just maintain a plan of food avoidance, as the child gets older, that can be harder to enforce (who didn't share lunches in school?). Anyway, many of your daughter's allergies may not ultimately end up being *true* allergies, but just *potential* allergies that the Mother blew out of proportion, given the real fear of true allergies.
That being said, given your autoimmune-mediated foot rash (likely eczema or psoriasis), your daughter may have inherited a tendency to have an over-active immune system. Nevertheless, time will be the best instrument in making that determination. And she may end up with no allergy issues at all.