Guide Disease Management of URDs With ImmunoCAP^®

What the profile will tell you

The ImmunoCAP^® respiratory profile is designed to accomplish two tasks:

1. To identify if a patient is allergic

2. To identify the categories of allergens to which the patient is sensitized

The regional respiratory profiles contain not only the allergens usually found within a geographic region, but also those known to have cross-reactivity with other allergens.¹ That is, if the profile for a specific area contains Bermuda grass, and the results are positive, the patient may be allergic to any of several grasses, because the allergic proteins for other local grasses can be similar enough to be recognized by the specific IgE for Bermuda grass.

Treatment considerations

For treatment at the primary care level, it is not so important to know which grass is causing the reaction, as it is whether grass is part of the problem.  While grass pollen may be difficult to avoid, knowing that grass pollen in general is a contributing factor may lead to pretreatment prior to grass pollen season, or dosage increases during that period. In addition, if other, more avoidable allergen sensitivities are identified, the elimination of any of them may impact the total allergic load.^2,3

In the case of URD, negative results indicate no atopy (and non-allergic rhinitis), meaning most likely no prescence of histamine, hence, second generation antihistamines (eg, Claritin^®, Allegra^®, Zyrtec^®)* will not work.⁴ First generation antihistamines (eg, Chlortrimeton^®, Benadryl^®)* can provide symptom relief due to the anticholinergic (drying) effect. For non-allergic diseases the best patient treatment plan is likely an explanation that second generation antihistamines are not beneficial, and intranasal steroids and/or decongestants are the best choice.³ First generation antihistamines may well help during overnight (sleep) hours.

In URD, positive results indicate atopy, with the quantitative results in kU_A/L giving a suggestion of the major and minor contributors. Although not all allergens produce the same level of response and not all immune systems react the same way, generally the quantitative scores reflect severity of allergen impact.

The management of positive/allergic patients becomes two pronged:

1. With the knowledge provided in ImmunoCAP results, patients may be directed to undertake the environmental controls.⁵ Eliminating the major offending groups of allergens may have importance due to the “cumulative threshold response” of allergic disease.^2,3

2. Treat with nonsedating antihistamines or a leukotriene antagonist^3,5; adjust dosage as necessary. Once daily dosing of oral second generation antihistamine offers a convenient and readily compliant treatment choice for truly allergic patients.

*Each of these brand names is the registered trademark of its respective manufacturer.