Tips for Allergy Relief

by Food and Drug Administration (FDA)

Isn't it a beautiful spring day?

Those words used to drive me insane. Beautiful spring days in Maryland mean warm sunshine and gentle breezes. But drifting in those spring breezes is pollen. So much pollen, mostly from trees, that the air becomes hazy, making life miserable for people with pollen allergies like my son Paul.

Two years ago, sunny spring days didn't mean riding bikes and playing ball for 5-year-old Paul. They meant recess in the school library, a box of tissues at his desk, and eyes nearly swollen shut by the end of the school day. Once home, he took off his pollen-covered clothes, put on clean clothes, and spent his afternoons inside a closed house with air conditioning running even if it was a balmy 70 degrees Fahrenheit (21 degrees Celsius) outside.

Only rainy days were beautiful spring days to Paul.

But last spring wasn't as bad for him, and this spring — after nearly two years of allergy shots — he may finally be able to enjoy sunny spring days outdoors.

One treatment for people with allergies is injections of small amounts of the substances they're allergic to. This is called immunotherapy. Over time as the dose is increased, the patient becomes hyposensitized (less allergic) to the allergens because the body, for reasons not yet fully understood, becomes more tolerant to the offending substances. The symptoms, including sneezing and watery eyes — and the need for medication — are reduced or disappear.

People of any age can develop allergies. Heredity and allergen exposure are important influences in whether allergies develop. Moving from one part of the country to another, especially if the climates, and therefore the native plants, are different, can influence the severity and seasonality of allergic symptoms.

The Food and Drug Administration regulates the biological extracts in allergy shots. The extracts are used both to treat and to test individuals to determine exactly what causes their allergic reactions.

In addition to treating pollen allergy from trees, grasses and weeds, immunotherapy is also used to treat allergies to house dust mites, pets, molds found indoors and outside, and stinging insects such as honey bees, yellow jackets, hornets, and wasps.

Who Should Get Shots?

From the time he was 12 months old, Paul was miserable in the spring and, to a lesser degree in the fall, with a runny nose, watery eyes, and itchy skin. By his third birthday, the pollen allergies also triggered asthma attacks. Prescription medications didn't help much to relieve his symptoms, even with constant use.

All this made Paul a good candidate for injections.

"Shots work extremely well in patients that clearly have allergic symptoms, either allergy in their nose like allergic rhinitis or bronchial asthma, where outdoor allergens like tree, weed and grass pollens seem to be a major cause," says Stanley P. Galant, M.D., an allergist in Orange County, Calif., and a clinical professor and director of pediatric allergy at the University of California, Irvine.

Patients with allergies to molds, house dust mites (microscopic insects that feed on human skin cells found on furniture, bedding and carpets), and animal dander (tiny skin flakes animals continually shed) don't respond quite as well to shots as those allergic to outdoor allergens, he says. But standardization of extracts for cat dander and dust mites and overall better preparations have increased effectiveness even for these patients, he adds.

Immunotherapy doesn't begin until after skin tests or blood tests have determined the exact culprits.

"You have to show that [the patients] have IgE antibodies to the allergens in question," says John Yunginger, M.D., a member of FDA's Allergenic Products Advisory Committee and a pediatric allergist at the Mayo Clinic, Rochester, Minn.

The first time an allergic person is exposed to an allergen, the immune system produces a kind of antibody called immunoglobulin E — IgE for short. (But it is rare for a first exposure to cause allergic symptoms. Only on subsequent exposures do typical allergic symptoms, such as sneezing, coughing and rash, appear.) Overproduction of IgE is characteristic of allergy reactions.

Deciding which allergens to test "depends very much on the patient's history," says Yunginger. "In somebody who has fairly straightforward classical seasonal symptoms they may get as few as 15 or 20 [skin] tests. Someone with more extensive perennial disease may get 75 or 80."

Each individual skin test consists of a small amount of the suspect allergen scratched onto the skin, usually on the back. If a hive with surrounding redness appears within 15 minutes, allergy to the substance is probable. The doctor also takes into account the dose of allergen and the size of the response.

Two controls, standards against which experimental observations may be evaluated, are also used to make sure skin-test reactions are caused by the allergens. One of the controls, which should not cause a reaction (no hive), is simply the diluting solution. The other control contains histamine, a naturally occurring substance that causes a hive in almost everyone.

According to Galant, the patient's history is as significant as the testing. "The history is really what tells me whether to put the patient on shots," he says. "Training as a specialist helps me interpret the data from the history and correlate that with the testing and come up with a solution."

While skin tests give quick results and can be done in the doctor's office, there are some cases where a blood test is preferable, says Marshall Plaut, M.D., chief of the allergic mechanisms section in the National Institute of Allergy and Infectious Diseases, National Institutes of Health. Individuals with skin problems or skin diseases are not good candidates for skin tests, he says.

About the Author

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FDA is A United States government body that oversees medical devices, including contact lenses, intraocular lenses, excimer lasers and eyedrops. In the US, these products must be approved by the FDA before they can be marketed.