Allergies Community

Dear Reddith,
Your case brings up some inconsistencies and I would suggest getting a second opinion from a board certified allergy specialist, or re-addressing the diagnosis with your current doctor.

Firstly, if the true diagnosis is Non-allergic rhinitis, it might be questionable to treat this with oral antihistamines. Some allergists would treat non-allergic rhinitis with saline lavage, antihistamine nasal sprays, steroid nasal sprays, or anticholinergic nasal sprays. I would suggest asking your immunologist/allergist if an alternative medication that is less drowsy may be used since you cannot tolerate the current regimen.

Secondly, the serum tests for specific IgE do have a lower limit of detection (typically <0.35) which means that it is possible to have a level of 0.34 that is clinically significant. It would show up as undetectable on the result, but that does not necessarily mean "negative."

Regardless of whether skin tests and serum IGE levels agree or do not agree, it is also important to consider what happens clinically. If you are around cats, touch them, hug them, hold them, etc, what happens to you? If you get itchy eyes, runny nose, sneezing, etc, then the skin tests are most likely true.

Tests are useful tools for allergists to use, But we must always interpret them in the clinical context of the patient. For instance, if you told me that you had nasal congestion all winter long from October through February, and skin testing revealed that you were only allergic to Grass pollen, I would probably say that something else is going on (like winter time viral illnesses). The season of grass pollen exposure is in the summer, not in the winter, and just going by the testing is not enough. It could be a trigger for summertime symptoms, but the important part of the evaluation is combining the history with the test results to come up with the diagnosis.

Some folks may have a low level of antibody but it has stronger binding and may be clinically relevant. The difference between a skin test and a blood test is that the skin test is a functional test. It suggests that the allergen is identified by the antibody, which induces mast cell release of histamine and other mediators which then leads to a large skin hive, itching, and redness. The blood test only demonstrates if there is presence of antibody or not.

Another confounding issue is that you might have a very sensitive skin condition called dermographism or dermatographism, which may make skin test interpretation difficult. This could result in false positive skin tests when in reality the allergy doesn't exist.

Bottom line is, I would make sure that you discuss your diagnosis again (make sure that the doctor feels comfortable with the diagnosis in the first place because this determines the treatment) and also your treatment failure (that you cannot tolerate the current medications) to find another medication that you can tolerate.

Good Luck!
ML