Allergic Disease

Cox, Linda, MD, FAAAI, FACAAI ACP
Associate Clinical Professor of Medicine
Nova Southeastern University
Fort Lauderdale, FL
Also by this Author 

Strategies For Optimum Patient Management

“Allergic disease is one of the most common and costly chronic diseases in both pediatrics and adults,” says Dr. Linda Cox, Allergist in private practice in Ft. Lauderdale). “It’s prevalent, it’s rising and it represents a significant healthcare cost”.

Dr. Cox discusses the rising trend in allergic disease and reviews diagnostic and treatment strategies, which can help reduce its burden on patients and the healthcare system.

A Widespread Condition – And Increasing

50 million people in the United States - 1 in 5 Americans – suffer from allergy. It is the 5th leading chronic disease in the U.S. and the 3rd most common disease among children under 18 years old of age. Individuals with allergies are at heightened risk for other diseases, including asthma. Allergic rhinitis is the most commonly diagnosed allergy among adults, while skin allergies and respiratory allergies are those most commonly diagnosed among children. Allergies account for more than 17 million physician office visits, 30,000 emergency room visits, and several hundred deaths each year.1

Allergic diseases are on the increase worldwide. “There are a couple of theories for the rising incidence of airborne allergies,” explains Dr. Cox. “One is called the ‘hygiene hypothesis’, which suggests we treat infections too quickly, rather than letting the immune system evolve naturally. The other relates to air pollution. This probably plays a role in several ways but we know that it has been shown specifically to increase allergenicity from ragweed and allergenic plants. Increased exposure to allergens in buildings, to dust mites and cockroaches, is also likely a contributing factor. There has also been an increase in food allergies, which are estimated to affect 6-8% of the pediatric population and 2% of adults. ”

Diagnostic Information to Guide Treatment

Accurate diagnosis is essential to determine appropriate patient management. “Allergic treatment includes medications, appropriate avoidance measures and immunotherapy,” observes Dr. Cox. ”But to offer appropriate measures or select a treatment you need to perform allergy diagnostic testing.”

For Dr. Cox, obtaining accurate information to guide patient management is essential. “I can’t stress enough how important it is to obtain good diagnostic information,” she says. “Taking inappropriate environmental measures costs both money and time, while not taking timely measures can have a cost to the patient, as their disease becomes more advanced.”

Testing options include skin prick testing, blood testing and food challenge. The skin prick test is typically administered by exposing the skin to small amounts of suspected allergens. The allergy blood tests look for specific immunoglobulin E (IgE) antibodies in the blood that are produced by the body’s immune system when an allergen is present. IgE blood tests, of which ImmunoCAP is considered the accepted standard 2,3, can be used to help diagnose sensitization for specific allergens, as well as to help guide treatment decisions.”4, 5

Guidelines for the diagnosis and management of asthma recommend that patients with persistent asthma be evaluated for sensitivity to aeroallergens.6 For rhinitis there is no such specific guidelines but, says Dr. Cox, if rhinitis is associated with co-morbid conditions like asthma or frequent respiratory infection it would be appropriate to refer for an allergy evaluation.

Allergen Immunotherapy

In considering therapeutic options, Dr. Cox stresses that the only intervention that modifies underlying allergic disease is specific allergen immunotherapy. Other medications simply control symptoms.

The allergen immunotherapy currently approved in the United States is the sub-cutaneous formulation, whereas a sub-lingual formulation has been used in Europe for many years. The availability of this more convenient form, which can be administered at home, has led to more widespread use, observes Dr. Cox. Several companies have been conducting trials of sub-lingual formulations in the U.S. and it is hoped FDA approval will be received for these therapies in the near future.

Dr. Cox believes this would help expand the population who can receive this kind of treatment. “Only 2 - 6 % of the appropriate population for allergen immunotherapy receive it,” she points out, ”So we’re talking about 95% who are managing it themselves or who are receiving various types of other treatment (that control but do not modify the allergic disease) from their physicians. I think some non-allergy trained health care professionals, still perceive allergen immunotherapy as an unproven method and don’t understand the potentially disease-modifying effect that it has. There has also been evidence that it can prevent asthma and can prevent the development of new allergies.”

Allergy March

Allergies have been shown to progress along a pattern known as the Allergy March, or Atopic March, but this natural progression can de interrupted by allergen immunotherapy. As Dr. Cox explains, “Several studies have shown immunotherapy can prevent the development of asthma in people with allergic rhinitis. It also seems to prevent the development of new allergy sensitivities, particularly in individuals who are allergic to a single allergen. So if you take children who are dust mite allergic and immunize them you may prevent a significant proportion from developing new allergies.”

“Other studies,” she adds, “have demonstrated that immunotherapy can prevent asthma in the population that were dust mite and grass allergic. This preventive effect seems to be lost as the allergy progresses, so there is some argument for early intervention.”

Reducing Healthcare Costs

Early, appropriate intervention with allergy therapy can also have a significant impact on healthcare costs. Recent studies by Cheryl Hankin, PhD and Dr. Cox in the Florida Medicaid population looked at new onset allergic rhinitis patients who received immunotherapy against a matched control who did not receive treatment.7, 8.

“12 year data showed there were cost savings of 30-40% in the 18 month period post-immunotherapy compared with the matched control,” says Dr. Cox. “With the children we saw reductions in pharmacy and outpatient utilization, while with the adults we also saw significant reductions in hospitalization. That’s hugely important because it says identifying and treating the allergen may not only prevent and improve symptoms but, in the bigger picture, it may reduce healthcare costs.”

References

  1. Asthma and Allergy Foundation of America.
    http://www.aafa.org/display.cfm?id=9&sub=30
  2. Dolen WK. IgE antibody in the serum – detection and diagnostic significance. Allergy. 2003;58:717-23.
  3. Yunginger JW, Ahlstedt S, Eggleston PA, et al. Quantitative IgE antibody assays in allergic diseases. J Allergy Clin Immunol. 2000;105:1077-84.
  4. Johansson SG, Yman L. In vitro Assays for Immunoglobulin E. Methodology, indications, and interpretation. Clin Rev Allergy. 1988;6:93-139.
  5. Wang J, Godbold JH, Sampson HA. Correlation of serum allergy (IgE) tests performed by different assay systems. J Allergy Clin Immunol. 2008;121:1219-24.
  6. Guidelines for the Diagnosis and Management of Asthma; National Heart Lung & Blood Institute, National Institutes of Health
  7. Hankin, C.S., L. Cox, and A. Bronstone, The health economics of allergen immunotherapy. Immunol Allergy Clin North Am, 2011. 31(2): p. 325-41
  8. Hankin, C.S., et al., Allergen immunotherapy and health care cost benefits for children with allergic rhinitis: a large-scale, retrospective, matched cohort study. Ann Allergy Asthma Immunol, 2010. 104(1): p. 79-85


Released on Wednesday, November 02, 2011