Identification of specific antigens via immunoglobulin E quantitative assaying of allergens (IgEQAA) can guide patients with atopic dermatitis to make lifestyle changes to improve outcomes, according to a study recently published in the International Journal of Dermatology.
IgEQAA, also known as radioallergosorbent testing, is an in vitro method of testing for a patient’s reactivity to different environmental allergens. Used to identify triggers in allergic rhinitis and asthma, a number of studies are also showing it may be a valid indicator of atopic dermatitis severity. The study authors sought to identify a correlation between IgEQAA score and atopic dermatitis severity and to assess whether knowledge about IgEQAA score could improve clinical outcomes via patient lifestyle changes.
The retrospective study was inclusive of 54 patients with a confirmed diagnosis of chronic atopic dermatitis. Average age was 42.9 years and ranged from 1 to 100 years. Average affected body surface area at presentation was 16% and ranged from trace levels to 80.5%. Average total IgE concentration was of 2682.7 IU/mL (range, 3.4-41,469 IU/mL), and abnormally high total IgE concentrations (>150 IU/mL) were detected in 76% of patients.
A diagnosis of severe atopic dermatitis was made in 45.5% of patients who showed sensitivity to the dust mite Dermatophagoides farinae, 47.0% of those with a sensitivity to the dust mite Dermatophagoides pteronyssinus, 50.0% of those with a sensitivity to dog dander, and 60.0% of those with a sensitivity to cat dander. Almost 52% of patients allergic to D. farinae and 52.9% allergic to D. pteronyssinus, 12.5% allergic to dog dander, and 10.0% allergic to cat dander had an IgEQAA class of 6.
The researchers found, however, that lifestyle modifications could ameliorate symptoms of atopic dermatitis. They reported that atopic dermatitis nearly cleared in a patient allergic to dust mites when he moved from an “older, rundown home” to a new condominium. Atopic dermatitis improved in patients who slept with their dogs despite being allergic to dog dander when the dog was removed from the bedroom. Likewise, atopic dermatitis cleared in patients who were cat owners but sensitive to cat dander when they limited their exposure to cats.
The study authors noted that, although allergists tend to rely on IgEQAA, it is not widely used among dermatologists, but perhaps should be. They argued that IgEQAA is easier to perform than skin prick testing and may be helpful in some patients who are not adequately responding to conservative treatment. Although they conceded that further studies are needed, their data suggest that IgEQAA testing may aid some patients in making lifestyle changes that improve treatment outcomes.
IgEQAA testing, used to identify specific environmental allergens, was shown to be useful in identifying causes of atopic dermatitis. This knowledge allowed a number of patients to make lifestyle changes, resulting in improved treatment outcomes.
Will BM, Severino R, Johnson DW. Identification of allergens by IgE-specific testing improves outcomes in atopic dermatitis [published online June 20, 2017]. Int J Dermatol. doi: 10.1111/ijd.13673