Hi J.,
I concur with Nicole that atopic dermatitis is frequently a symptom of food allergy. If either you, your husband, or any of your other children have allergic symptoms, this increases the likelihood that your baby is or will be allergic to something (atopy specifically refers to allergy with a hereditary basis).
The most common food allergen culprits in infants and children are milk, eggs (whites), corn, wheat, tree nuts, and fish. If you're breast feeding, you might try eliminating each of these in turn from your diet for two weeks and see if your son's rash improves. If so, practice strict avoidance of the identified food to reduce your son's sensitization to the allergen. If you're formula feeding, try switching to a hypoallergenic formula (one that is based on hydrolyzed proteins).
If it does appear that allergy is responsible for the rash, seek out a reputable allergist. Please avoid NAET. I know Nicole is a big proponent of it, but several medical organizations are requesting that NAET practioners be brought to the attention of and investigated by the state's attorney general. The practice has no basis in physiology or immunology, and simply does not make scientific sense. NAET practitioners diagnose allergy at a rate that is 60 times greater than the prevalency estimated by epidemiologists (scientists who specialize in tracking disease trends in populations). No paper on NAET has ever been published in a reputable medical journal. The only papers that have been published were self published and not peer-reviewed by recognized allergy experts.
BTW, there was a recent article in the NY Times (Feb 2) on appropriate testing for food allergies. The article suggested that the only appropriate way to test for food allergies was the use of oral challenge. (This would be in older children in adults: testing is not typically carried out in infants under the age of two, although blood testing can be accomplished.)
Unfortunately, the reporter got a lot of her information more than a little mixed up. The study that she was reporting on was published by Dr. Robert Wood (I read this study when it first came out in 2007), which she claimed showed that blood testing was not an accurate method of allergy diagnosis. In actuality, Dr. Wood was comparing the accuracy of 3 different allergy blood test systems from the three leading manufacturers: Phadia, Siemens, and Hycor. His study showed that there were differences in the three assays that labs needed to be aware of when reporting results, but it did NOT say that the tests were not accurate for aiding in the diagnosis of allergy. It is my understanding that Dr. Wood and Dr. Robert Hamilton (another expert on allergy testing at Johns Hopkins) are discussing sending an editorial to the Times to correct the errors in Ms. Parker-Pope's article, although I do not know what their final decision will be. BTW, Ms. Parker-Pope is NOT a member of the American Medical Writer's Association, so I cannot check on her credentials or background, and therefore cannot make comment on her level of understanding of this topic.
It is true that indiscriminate and improper use of allergy blood tests can lead to false-positive results. It is important to understand that they should only be used to confirm the identity of specific allergens when clear symptoms and patient history indicate the need for testing. Using them as a screening test for the general population is not part of the intended use as approved by the FDA.
As for the statement that food challenge is the only approved method for diagnosing food allergies, this is in contradiction to the practice guideline for food allergy testing published by the American Academy of Allergy, Asthma and Immunology (aaai.org)in 2006. This guideline states: "The primary tools available to diagnose adverse reactions to foods include history (including diet records), physical examination, skin prick or puncture tests, serum tests for food specific IgE antibodies, trial elimination diets, and oral food challenges." It continues: "The diagnostic tools available to the clinician include simple and relatively inexpensive tests, such as the clinical history, physical examination, skin prick or puncture tests, and serum tests for food specific IgE. Additional tests (oral food challenges) are more involved timewise, may be more expensive, and may carry additional risks. The rational selection and interpretation of diagnostic tests require an appreciation for the utility of the tests themselves and an evaluation of the level of certainty required for the diagnosis."
It is not surprising that the doctors quoted in the article are proponents of oral challenge -- this is what they specialize in at National Jewish Health, which is, BTW, a very fine organization with excellent researchers and clinicians. However, there are not many places or allergists in general who will do an oral challenge, for exactly the reasons stated by the aaaai. It is expensive and it does carry inherent dangers if there is any chance of a severe reaction and/or anaphylaxis. When such testing is done, it is mandatory that emergency injections of benadryl and epinephrine, a crash cart for cardiac resuscitation and intubation tray for opening a closed airway be at hand.
Good luck with your little one!
