5 Don'ts in Allergy and Asthma Testing
Editor's Note:
Choosing Wisely®, an initiative of the ABIM Foundation, currently comprises evidence-based recommendations from 9 specialty organizations on commonly used tests and procedures, with more recommendations planned from other societies later in the year. The goal is to use these recommendations as the basis for discussions between clinicians and patients. Medscape interviewed David M. Lang, MD, an officer of the American Academy of Allergy Asthma & Immunology (AAAAI) who helped craft its Choosing Wisely recommendations.
Medscape: Would you give a brief history of AAAAI's involvement in the Choosing Wisely campaign and why you believed this would be important?
Dr. Lang: There was an article in the New England Journal of Medicine by Howard Brody, MD, PhD, in 2010, and I believe that's what sparked this initiative. In that article, titled "Medicine's Ethical Responsibility for Health Care Reform -- The Top Five List," Dr. Brody challenged providers and specialty groups from both primary care and specialty areas to develop a top 5 list for each specialty, where stopping or restricting these 5 procedures, diagnostic tests, and therapeutic interventions would save the most money without compromising patient care. The list would cover "diagnostic tests, treatments, and interventions that are very commonly ordered by members of that specialty, that are among the most expensive services provided, and that have been shown by the currently available evidence not to provide any meaningful benefit to at least some major categories of patients for whom they are commonly ordered"; that's a quote from the article.
AAAAI elected to join the American Board of Internal Medicine initiative, and in the context of our participation, a task force was created to lead the effort on Choosing Wisely. The task force consisted of members of the board of AAAAI, the academy's president, and other officers and members of its Joint Task Force on Practice Parameters.
We opened this up to the membership to submit ideas for relevant diagnostic tests or therapies for consideration, and then from that list and from our own suggestions, we evaluated candidates for our top 5 list. We looked at their appropriateness, their relevance to the specialty of allergy and immunology, the potential overuse of resources, opportunities to improve patient care, and the evidence demonstrating that such diagnostic tests or therapies have not been associated with improved patient care outcomes. We refined our list, and what you see in terms of our top 5 reflects the end result of these efforts.
Medscape: I'd like to go through the recommendations and ask you how they were selected. Could you also speak briefly about the evidence behind the recommendations? The first recommendation is: Don't perform unproven diagnostic tests, such as immunoglobulin G (IgG) testing or an indiscriminate battery of immunoglobulin E (IgE) tests, in the evaluation of allergy.
Dr. Lang: The presence of IgG antibodies to a food does not correlate with having an adverse reaction in association with consuming that food . Commercially available IgG antibody tests can be obtained for food allergy testing, but there is no association between the presence of these specific IgG antibodies in somebody's blood tests and the presence of allergic disease.
For this reason, IgG testing in the evaluation of patients with allergy or suspected allergy has not been proven to be associated with improved outcomes, and specific IgG testing shouldn't be obtained in the evaluation of patients with suspected allergic disease.
IgE is the class of antibodies that participate in allergic reaction. But the IgE testing that is cost-effective and associated with improved patient care outcomes is that which is based on a patient's history. So if someone, for instance, has had a reaction that is temporally associated with eating shrimp, obtaining serum-specific IgE for shrimp -- via either skin or blood testing -- would be appropriate. Testing for related foods (such as crab and lobster) may also be appropriate. However, ordering an indiscriminate battery of tests -- for instance, IgE for beef, chicken, lettuce, and tomatoes -- when the patient's reaction was associated with consuming shrimp, would not be appropriate under most circumstances.
The point is that in obtaining IgE testing, the history should guide the healthcare provider in terms of which test(s) to order.
Medscape:Your second recommendation is:Don't order sinus CT or indiscriminately prescribe antibiotics for uncomplicated acute rhinosinusitis.
Dr. Lang: Viruses are the cause of the majority of acute rhinosinusitis or acute sinusitis episodes, and only a small proportion of these episodes progress to bacterial infection. Because viruses cause most of these episodes, antibiotics are not efficacious and are not associated with improved outcomes. Most acute rhinosinusitis episodes resolve without treatment within in a week or two, and for this reason, an imaging study, such as sinus CT, is not required.
In patients who have mild illness, antibiotics aren't required, but for patients, for instance those with a temperature above 101.5° F, purulent secretions, and/or unilateral pressure sensation, administration of antibiotics may be appropriate. If this is the case, amoxicillin should be regarded as the first-line antibiotic treatment for most episodes of acute rhinosinusitis.
Medscape:Your third recommendation is:Don't routinely do diagnostic testing in patients with chronic urticaria.
Dr. Lang: In the overwhelming proportion of patients with hives (urticaria) that persist longer than 6 weeks, a definite cause is not identified. In most cases, limited testing can be considered, and certainly, targeted laboratory testing based on clinical suspicion would be appropriate. For instance, in patients with an extensive travel history; a significant exposure history; or symptoms and signs that suggest an underlying disorder, such as a thyroid condition, appropriate laboratory testing is indicated.
However, in patients with an otherwise unremarkable history -- including comprehensive review of symptoms -- and physical examination findings, routine extensive testing is not cost-effective and has not been associated with improved clinical outcomes. Routine skin testing or serum specific IgE testing for inhalants or foods is also not warranted unless there is a clear history implicating an allergen as a provoking or perpetuating factor for urticaria/angioedema.
Medscape:Your fourth recommendation is:Don't recommend replacement immunoglobulin therapy for recurrent infections unless impaired antibody responses to vaccines are demonstrated.
Dr. Lang: Patients with humoral immune deficiency need to be identified so that they can receive replacement immunoglobulin therapy. Such patients have a history of frequent, recurrent, or unusual infection and demonstrate impaired antibody responses to tetanus and/or pneumococcal vaccination. However, gamma-globulin replacement therapy is associated with substantial direct and indirect costs and is not indicated for patients who have hypogammaglobulinemia without demonstrated impaired antibody responses to vaccines.
We commonly see this, for instance, in patients who have taken corticosteroids and have secondary hypogammaglobulinemia but who manifest a normal response when challenged with vaccines. The administration of gamma-globulin to such patients is not cost-effective, nor is it associated with improved patient care outcomes.
Medscape: And your fifth recommendation is: Don't diagnose or manage asthma without spirometry.
Dr. Lang: Without an objective measurement of lung function -- such as spirometry -- both patient and physician are prone to underestimate severity of asthma and overestimate response to treatment. For this reason, healthcare providers who rely on symptoms when diagnosing and managing asthma can be misled, and this may lead to undertreatment of patients with asthma.
Spirometry is essential not only for the appropriate management of patients but also frequently to confirm the diagnosis of asthma.
Recent asthma guidelines underscore the importance of spirometry in terms of estimating disease severity and monitoring asthma control over time. Spirometry is essential in the management of asthma. Objective measurements of lung function should be obtained in patients with asthma periodically over time to ensure that asthma is appropriately controlled.
Medscape: Thank you, Dr. Lang. Do you think there are any further recommendations that AAAAI might be adding down the road? And are there any other Choosing Wisely activities coming up in the near future?
Dr. Lang: The response we've had from healthcare professionals and consumers has exceeded our expectations, and we intend to continue to pursue opportunities related to the current recommendations before considering the addition of new recommendations. We look forward to new activities generated by the Choosing Wisely campaign.