Allergies Archive

Research we're watching

Some new research shows good reason to focus on reducing the number of indoor allergens in your home. A new study published in the Nov. 30, 2017, issue of The Journal of Allergy and Clinical Immunology found that more than 90% of nearly 7,000 homes studied had three or more detectable allergens, from a list of eight common allergens. In addition, some 73% of homes had one allergen found at levels researchers defined as "elevated." The researchers used data from the 2005–2006 National Health and Nutrition Examination Survey. The eight allergens were cat, dog, cockroach, mouse, rat, mold, and two types of dust mites. Factors that led to higher levels of indoor allergens included pets and pests. Certain types of homes were also more likely to have higher allergen levels, including older homes, rental homes, mobile homes, and homes in rural areas.

Research we're watching

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If you have an egg allergy, you may have been told not to get a flu shot. That's because the vaccine is grown in eggs and may contain a small amount of egg protein, which — it was feared — could trigger an allergic reaction. But a new guideline from the American College of Allergy, Asthma and Immunology (ACAAI) dispenses with that old advice and says even people with an egg allergy should roll up their sleeves and get the shot to protect themselves from the flu.

"When people get flu shots, health care providers often ask if they are allergic to eggs," allergist Dr. Matthew Greenhawt, chair of the ACAAI Food Allergy Committee and lead author of the practice parameter, said in a written release. "We want health care providers and people with egg allergy to know there is no need to ask this question anymore, and no need to take any special precautions. The overwhelming evidence since 2011 has shown that a flu shot poses no greater risk to those with egg allergy than those without." Numerous studies have found that patients with egg allergy — even those with life-threatening allergies to egg — have gotten the shot and did not suffer any ill effects. This suggests there isn't enough egg protein in the vaccine to cause a reaction.

News briefs

Spring is on the way, which means allergy season is around the corner. But it's not just springtime pollen that can trigger a runny nose and itchy, watery eyes. Indoor allergens — such as mold, pet dander, and dust mites — can lead to allergy symptoms in some people or make allergy and asthma symptoms worse. And a study published Nov. 30, 2017, in the Journal of Allergy and Clinical Immunology found that 90% of homes have three or more allergens, with at least one allergen at high levels in 73% of homes. Researchers combed through information collected in a large national survey that also assessed allergen levels in bedroom dust collected from nearly 7,000 U.S. households. The presence of pets and pests (cockroaches, rodents) were the major contributors to high levels of indoor allergens in participating homes. Study authors recommend reducing indoor allergens by sealing entry points for pests, keeping pets out of the bedroom, and making sure each week to wash bedding in hot water and vacuum carpets and upholstered furniture.

Ask the doctors

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Q. Can adults develop food allergies, or is this possible only in children?

A. While food allergies are more common in children, adults can, and sometimes do, develop food allergies. You can become allergic to a food you've eaten without a problem for years, or a childhood allergy that disappeared can re-emerge. Certain foods are more likely to trigger allergic reactions than others, such as tree nuts, peanuts, shellfish, milk, and wheat.

The inflammation of chronic sinusitis can be more than just an annoyance. Here's what you can do about flare-ups.

Stuffy nose? Constant blowing? A head on the verge of exploding? Everyone battles clogged sinuses at times, and often the discomfort goes away after a few days. However, if the condition lingers or becomes more severe, you could be battling chronic sinusitis, which can affect your quality of life.

"Besides the stress of dealing with the symptoms, the condition can interfere with your sleep, lead to depression, and keep you from being active," says Dr. Ahmad R. Sedaghat, an otolaryngologist with Harvard-affiliated Massachusetts Eye and Ear Infirmary.

News briefs

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Unless you have celiac disease, banning gluten from your diet won't boost your heart health—and may actually hurt it, suggests an observational study published May 2, 2017, in The BMJ. Gluten is a protein in wheat, barley, and rye. In people with celiac disease, eating gluten triggers the body to attack the small intestine, causing inflammation and leading to malnutrition and gastrointestinal distress. The inflammation, in turn, can increase heart disease risk. In these people, eliminating gluten stops the attack on the small intestine, reduces inflammation, and helps reduce heart disease risk.

A Harvard research team wondered whether people without celiac disease might also lower their heart disease risk by eliminating gluten from their diets. In a study of more than 110,000 healthy men and women followed for about 25 years, the researchers did not find a clear difference in the number of heart attacks that occurred among people who ate the most gluten each day, compared with people who ate the least. However, in people who avoided gluten by avoiding whole grains — which contain valuable nutrients — the risk of heart disease rose. So, if you're among the great majority of people who don't have celiac disease, avoiding gluten won't reduce your risk of heart disease, and it might increase the risk if it means you cut back on whole grains.

Fighting back against tiny allergens before they strike can help you avoid or reduce symptoms.

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The spring allergy season begins next month, and if you want to avoid symptoms, you must act now. "Pretreating allergies will lead to better control of symptoms, and maybe prevent symptoms from showing up," says Dr. Ahmad Sedaghat, an ear, nose, and throat specialist at Harvard-affiliated Massachusetts Eye and Ear Infirmary.

Automatic defenses

When spring allergens—typically pollen from oak, elm, birch, poplar, or maple trees, depending on where you live—float through the air and reach the nose, the body sometimes overreacts. Mast cells in the lining of the nose mistake the harmless tree particles for dangerous invaders, and summon help by releasing chemicals such as histamine and tryptase, which then recruit more immune system cells to the battle.

People with allergies to grass pollen may have cheered last year when the FDA approved a no-needles treatment —a daily tablet you dissolve under your tongue. These tables deliver low doses of grass pollen to the bloodstream. This is done to “teach” the immune system not to wage war on grass pollen. It turns out that these tablets don’t work that well. An analysis of 13 controlled clinical trials indicates that dissolvable tablets are only slightly more effective than placebos in curtailing classic symptoms of grass pollen allergy—runny nose, itchy eyes, and tickly throat. To make matters worse, more than 60% of people who used the tablets experienced irritating side effects.

Allergies can cause great misery. Luckily, there are options to help manage symptoms and continue doing the things you enjoy. The goal is to find the treatment that best suits your allergies, your lifestyle, and your wallet. Here are three of the most common ways to find relief from allergy symptoms.

Antihistamines

These medications are the mainstay for treating the sneezing, runny nose, and itchy eyes that come with allergies. Antihistamines also relieve hives and other symptoms of some food allergies.

Many people who suffer from hay fever (seasonal allergic rhinitis) are familiar with the older antihistamines such as diphenhydramine (Benadryl) and chlorpheniramine (Chlor-Trimeton). While these drugs work well, they leave many people feeling groggy, sleepy, or just "out of it." Thankfully, the newer generation of antihistamines, including cetirizine (Zyrtec), desloratadine (Clarinex), fexofenadine (Allegra), and loratadine (Claritin), are far less likely to cause drowsiness at recommended doses. Their effects are also longer lasting, so usually you need to take them only once a day instead of every four to six hours.