Monday, November 10, 2008

Allergies, Asthma, and the Presidential Pet

By Alvin M. Sanico, M.D.

There has been increased interest in "hypoallergenic" dogs since Barack Obama brought up the topic in his first post-election press conference. The main concern is that his daughter Malia has asthma and allergies, so the wrong canine choice could lead to a disappointing - if not seriously detrimental - outcome. The president-elect already faces many crises that need to be addressed, so it would be in everyone's best interest to take a potential problem off his plate. This brief article could provide useful insight not only for the future First Family but also for others in a similar situation.

The quest for a “hypoallergenic” dog (or cat for that matter) is a natural consequence of the high prevalence of asthma and allergies combined with the high percentage of households that have pets. The American Academy of Allergy, Asthma and Immunology cites that in the US, at least 20 million people have asthma and this problem accounts for an estimated 5000 visits to the emergency department, 1000 hospital admissions and 11 deaths every single day. Asthma can be affected by various factors including sensitivity to indoor allergens. In the Institute of Medicine report Clearing the Air: Asthma and Indoor Air Exposures, it was concluded that asthma exacerbation is associated with exposure to allergens from cats, cockroaches, dust mites, and dogs among those who are sensitized to these allergens.

Such sensitivity can easily be demonstrated by needle-free allergy skin testing that reveals results in 20 minutes. If the test is negative, then any concern about dogs in relation to allergies and asthma would be unwarranted. If the test confirms sensitivity, then it definitely should be part of the disease management discourse. The fundamental problem in allergies and asthma is inflammation that develops upon exposure to relevant allergens. The treatment strategy should thus include avoidance of such exposures, which can be effective but certainly not easy to accomplish. Indeed, a USA Today Snapshot showed that 45% of households with pet allergy sufferers kept a dog or cat knowing that the pet causes a reaction.

The Humane Society reports that about 39% of US households have one or more dogs, and nearly 34% have at least one cat. Pets are clearly part of the family fabric in many American homes, so while talks about avoidance can lead to positive results, they are understandably often futile. The current talks about “hypoallergenic” dogs, on the other hand, can lead to negative outcomes if they perpetuate a myth and create unfounded expectations.

The fact is that all dogs and cats produce allergens that can be found in their dander and saliva, regardless of their breed and the length of their hair, or lack thereof. Some may produce more - or less - allergens than others simply because of their individual nature. Based on this premise, it wouldn’t really matter if the Obamas choose a "mutt" over the various breeds that pet pundits now suggest.

The American Kennel Club reported that the Poodle won in a poll where more than 42,000 votes were cast to choose the “hypoallergenic” breed for the Obamas. This is highly ironic, because a study by Ramadour et al published in the journal Allergy in 2005 showed that mean levels of the allergenic protein Can f 1 were highest in dander from Poodles and surprisingly lowest from Labrador retrievers. A key finding was that Can f 1 levels varied significantly within the same breed. The authors concluded that “we can advise patients to choose Labrador dogs over another breed but the variability from one dog to another in the same breed shows that a 'hypoallergenic dog breed' does not exist."

Given that the president-elect cannot renege on his promise to get a puppy, other approaches need to be considered at this point. Before the choice is finalized, a reasonable trial period would be advisable to test whether, and to what extent, exposure to any candidate dog triggers symptoms. Control of allergy and asthma need to be optimized and maintained with appropriate medications. Allergen immunotherapy may be considered, with the understanding that it would take several months before desensitization can be achieved. With the right strategy, the chosen dog could provide joyful companionship instead of consternation.

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Dr. Alvin M. Sanico is the Director of the Asthma Sinus Allergy Program at Greater Baltimore Medical Center and an Assistant Professor of Medicine at the Johns Hopkins Division of Allergy and Clinical Immunology. He is a Fellow of the American Academy of Allergy, Asthma and Immunology.