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Asthma Among the Ruins

Study says egg patina on old stone buildings may cause allergic reaction

FRIDAY, Oct. 5, 2001 (HealthDayNews) -- Doctors in Spain have discovered what they think is a rare and hidden source of egg allergens: the decorative patina once used to coat the walls of ancient stone buildings.

After treating a 20-year-old woman hospitalized with an asthma attack and severe inflammation of her skin, nose and lung linings, an inflammation that covered 60 percent of her body, the doctors ran a series of allergy tests. Skin-prick tests turned up positive for grass pollen, cat dander, bird feathers, egg white and egg yolk. To see if eggs were the root of the breathing problem, they further tested her and found that within one second of eating the egg allergens, her breathing ability declined 20 percent. After starting an egg-free diet, the patient improved.

But 15 months later, she showed up in the hospital with another asthma attack and complained of inhaling the dust created by the restoration of an old cathedral opposite her home. Based on recent research that found milk proteins were often used in ancient pottery, the doctors suspected the walls of the cathedral might be to blame for the woman's high level of egg antibodies.

After obtaining a dust sample from the cathedral renovation site, doctors checked the allergenic response to the dust with the woman and 19 control patients. Of the 19 patients, 10 had asthma, five were egg-sensitive and four were workers at the cathedral site. The original patient, the five egg-sensitive subjects and one worker all had positive reactions, while the 10 with asthma had no reaction to the dust.

"We should keep in mind egg as a possible etiologic agent in patients who experience asthma after inhalation of dust from old monuments and as a potential cause of occupational asthma in workers laboring in building conservation," says Dr. Alicia Armentia, lead author of a study letter, which appears in this week's issue of The New England Journal of Medicine.

However, you needn't worry about the dust from stone buildings damaged in the Sept. 11 attack on the World Trade Center in New York City, she says.

"Egg was widely used to obtain the patina for stone coverings of many ancient buildings, but in the case of older stone buildings in lower Manhattan that were damaged by the attack on the Twin Towers, I do not think that egg was used in buildings constructed during the 20th century. Resins and other covering materials have been used more recently for this purpose," Armentia says.

One allergy expert says the findings don't quite make the connection between egg patina and an allergic reaction.

"There could have been egg allergen that got released in the air, so it may have caused the asthma," says Dr. Martha White, director of research at the Institute for Asthma and Allergy in Wheaton, Md. "They found it in the dust. They found the woman was allergic to it, so it's suggestive of that, but there's no definite proof. All they proved was there's something in the dust that can cause a reaction. They didn't prove that was what actually happened."

White says the doctors should have taken air samples from the construction site to measure the level of egg allergen floating in the air and whether that would have caused an allergic reaction in the patient.

"Scientifically, they're not quite there," she says.

Egg allergies are most common in infants and young children, although most outgrow the sensitivity by the time they are 5. Eggs are made of proteins that are highly allergenic. They include ovomucoid, ovalbumin, ovotransferrin and lysozyme. Ovalbumin, the major allergen, makes up 50 percent of an egg white.

Food allergies occur in 2 percent to 8 percent of children, and usually involve dairy and wheat products. Only 2 percent of adults suffer food allergies, and the most troublesome foods for them include tree nuts, fish, shellfish and peanuts. A typical allergic reaction can include swelling of the lips, stomach cramps, diarrhea, hives or a rash and difficulty breathing.

What To Do: For more on food allergies, visit the National Institute of Allergy and Infectious Diseases, the American Academy of Allergy, Asthma and Immunology or the Food and Drug Administration.

SOURCES: Interviews with Alicia Armentia, M.D., Hospital Rio Hortega, Valladolid, Spain; Martha White, M.D., allergist, director, research, Institute for Asthma and Allergy, Wheaton, Md.; Oct. 4, 2001, study letter The New England Journal of Medicine
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