Nov 25, 2013

Hypoallergenic Dogs Not Allergy-Proof

Although they've long been considered an allergy sufferer's best friend, so-called hypoallergenic dogs do not have lower household allergen levels than other dogs, according to a new study that measured allergen levels in babies' nurseries.

Dog breeds classified as "hypoallergenic" are believed to produce less dander and saliva and shed less fur. Researchers at the Henry Ford Hospital (HFH) in Detroit put this theory to the test by measuring environmental allergen levels in the houses of 173 dog owners one month after a newborn baby was brought home.

Researchers collected dust samples from the carpet or floor of each baby's bedroom and measured the levels of the dog allergen Can f 1. Only homes with one dog per family were involved in the study, and 60 dog breeds were analyzed overall, 11 of which are considered hypoallergenic dogs.

"We found no scientific basis to the claim hypoallergenic dogs have less allergen," said Christine Cole Johnson, chair of HFH's Department of Public Health Sciences and senior author of the study.

Dogs are often classified as hypoallergenic using one of four "schemes" based on their breed in order to compare allergen levels. Scheme A compares purebred hypoallergenic dogs to purebred non-hypoallergenic dogs, while scheme B compares purebred and mixed breed dogs with at least one hypoallergenic parent to purebred non-hypoallergenic dogs.

Scheme C compares purebred and mixed breed dogs with at least one hypoallergenic parent to purebred and mixed breed dogs with no known hypoallergenic component, and scheme D compares only purebred dogs identified as hypoallergenic by the American Kennel Club to all other dogs.

The study showed that all four schemes yielded no significant differences in allergen levels between hypoallergenic dogs and non-hypoallergenic dogs. In fact, in homes where the dog was not allowed in the baby's bedroom, the allergen level for hypoallergenic dogs was slightly higher compared to allergen levels of non-hypoallergenic dogs.

"Based on previous allergy studies conducted here at Henry Ford, exposure to a dog early in life provides protection against dog allergy development," Cole Johnson added. "But the idea that you can buy a certain breed of dog and think it will cause less allergy problems for a person already dog-allergic is not borne out by our study."

Nov 20, 2013

Allergy Shots Decrease Anxiety, Depression

Stinging insects are everywhere making them nearly inescapable. The thought of being stung can cause depression and anxiety for the two million Americans that are allergic to their venom.

But according to a study, allergy shots, also known as immunotherapy, can improve quality of life for these sufferers. Allergy shots are the only allergy treatment known to modify and prevent disease progression, and can be life-saving for those allergic to insect stings. Researchers have found this type of treatment also decreases anxiety and depression in those allergic to wasp, bee and ant stings.

Insect stings send more than 500,000 Americans to hospital emergency rooms and cause at least 50 known deaths each year. A person who has had an allergic reaction to insect sting has a 60 % chance of having another similar or worse reaction if stung again. Immunotherapy has been shown to be an astonishing 97 % effective in preventing future allergy to insect stings.

Nov 14, 2013

Fresh Air to Combat Allergies

New research has found that we may actually be able to reverse allergies, even in adulthood. The fix may be as simple as taking a trip to the country.

For 15 years, researchers from Aarhus University in Denmark followed nearly 1,200 people who were bound for jobs in either farming or the army. They tested the subjects' sensitivities to common allergens at the study's beginning and end while also following where they lived and worked. What they found was that people who worked on farms in adulthood were less likely to become sensitive to allergens. People who moved from urban to rural environments showed the greatest benefit, but there was also a positive effect seen in farmers who had a farm upbringing.

Why the change? Researchers think that the diversity of microbes and bacteria on farms may help people's immune systems develop a more appropriate tolerance against allergens. "It doesn't protect you from allergies to stay away from all allergens," says Grethe Elholm, a post-doc at Aarhus University and co-author of this study. "It actually seems to help to be exposed to a lot more of many different things because your immune system needs to work out." Still, the research is fairly preliminary, and follow-up studies are expected. So it may be best for those with bad allergies to tread lightly in highly pollinated places.

Nov 5, 2013

Antihistamines in pregnancy and risk of birth defects

Antihistamines are a group of medications that are used to treat various conditions, including allergies and nausea and vomiting. Some antihistamines require a prescription, but most are available over-the-counter (OTC), and both prescription and OTC antihistamines are often used by women during pregnancy. Until recently, little information was available to women and their health care providers on the possible risks and relative safety of these medications in pregnancy, particularly when it came to specific birth defects.

A new study from Boston University's Slone Epidemiology Center, based on interviews with more than 20,000 new mothers, now provides important information for many of these medicines. The researchers considered antihistamines that had been suggested in earlier studies to increase risks of certain defects, and they also considered other possible risks that might not have been identified in the past. Where there was sufficient information in the study data, the authors found no evidence to support suggestions of risk that had been found in earlier studies. In considering possible risks that had not been identified by others, the investigators found very few suggestions that any given medicine might be linked to an increase risk of a specific birth defect, and though these few deserve further research attention, these findings may have been due to chance.

Dr. Allen Mitchell, the study's director, noted that "we were fortunate that our study was able to consider commonly-used antihistamines that were available OTC as well as those available only with a prescription. While our findings provide reassurance about the relative safety of many of these medications in relation to a number of common birth defects, more information is needed. As is the case for all types of medications, women who are pregnant or may become pregnant should consult with their health care provider before taking any medicines, whether they are prescribed or OTC."