Millions of allergy sufferers dream of finding a place in the world where there are no substances to send them into spasms of sneezing and respiratory discomfort. But not only are such places difficult to find, a safe haven for one allergy victim may provoke discomfort in another.
Since most countries have the same or similar allergens, and allergy sufferers carry with them immune systems that predispose them to attacks, the likelihood of experiencing problems in other countries is great. But for the more than 40 million Americans suffering from allergies--and a good many of them traveling, at least from time to time--it is possible to minimize discomfort if a few preparations are taken.
One way to prepare is to learn if plants and other factors that induce allergic symptoms at home are present in the place to be visited. If so, knowing which months those allergens are at their peak can be useful when scheduling a trip.
Travelers in the United States may benefit from a guide to seasonal allergens prepared each year by Schering Corp., a major pharmaceutical company. It includes forecasts of the allergy season severity for various trees, grasses and weeds in each of six regions across the country. While August--the peak month for allergies in the United States--is almost over, allergy season will continue well into October in some places.
Copies of the Chlor-Trimeton Guide to Seasonal Allergens may be obtained free of charge by sending a self-addressed, stamped envelope to Chlor-Trimeton Guide, P.O. Box 5137, Dept. T, Bergenfield, N.J. 07621.
Finding out which allergens are prevalent in other countries is not always as easy. But a list prepared by the American Academy of Allergy and Immunology provides information for 16 countries and Hawaii.
Here are brief selections for several countries:
--Mexico: Bermuda grass is the most significant allergen in Mexico City. Its pollen is most prevalent in October, November and December. In arid northern Mexico, acacia and mesquite bloom in July and August. Molds and house dust mites are significant allergens in coastal areas.
--Australia: The warm and rainy coastline around Melbourne harbors dust mites and molds in the summer (October to May). For the country as a whole, rye, orchard grass, Holcus, timothy, barley and canary grass are the most significant plant allergens. They bloom from September until June and peak in November and December. Tree pollens are less threatening. Northern Australia is tropical and has fewer pollens, although the grass season is longer.
--France: In northern and central France, timothy, orchard, redtop, June and velvet grass are the cause of most pollen problems. Strasbourg in the northeast has a lot of birch pollen in April. Allergens from grasses that grow in the Alps reach their peak during June and July. Tree pollen season is March and April. On the Mediterranean near Nice and Marseille, the tree season runs from January to June. Also in Marseille, coffee and castor-bean processing factories can trigger asthma attacks.
Other countries on the list are Italy, Japan, Spain, Sweden, Switzerland, Germany, the Soviet Union, Austria, Canada, China, Czechoslovakia, Great Britain and Israel.
For a free copy of the list, call the American Academy at (800) 822-2762. The academy also offers information on asthma, and can refer travelers to 400 allergy specialists outside the United States.
But pollen and plants aren't the only problem. Allergic reactions can be caused by a variety of other substances.
For example, doctors at the National Jewish Hospital in Denver say that because mites thrive in feathers, stuffed furniture can cause problems for unsuspecting asthmatics. In warm, moist areas, even non-asthmatics can experience a constantly itchy nose due to exposure to mites, according to the physicians. Many European countries use feathers to stuff furniture.
Another potential problem is insecticides sprayed into some airlines upon landing to prevent the introduction of harmful pests into a country. Such spraying can prompt a chemical-caused allergy in some people. The United States stopped spraying incoming airliners in 1979, but it still is a common practice in some parts of the world, especially Africa and parts of Asia.
International experts debate whether spraying is effective enough in preventing the arrival of malaria-carrying mosquitoes, for example, to justify the toxic effects that the chemicals have on some people. Complaints from passengers reportedly were an important factor in the U.S. Public Health Service's decision to discontinue spraying. Dr. Sidney Friedlaender of the University of Florida suggests that travelers keep a cloth or paper face mask handy for protection. Spraying usually takes place after landing but before passengers disembark.
Face masks can also be used for protecting lungs from air pollution in such places as Bangkok, where toxic gases that were once blown away by the wind are now being trapped in the city by high-rise buildings, according to the Thailand Development Research Institute.
In Santiago last June, heavy smog caused large numbers of people to seek medical care for respiratory problems. Smog is also common in Mexico City.
Asthmatics would be wise to carry their own epinephrine, corticosteroids, needles and syringes, according to allergy specialists. Those who use inhalers should keep them in carry-on baggage to prevent them from exploding in the lower-pressurized airplane baggage compartment.
Chronic bronchitis sufferers prone to pneumonia might want to ask their doctor whether they would benefit from taking antibiotics temporarily to fend off pneumonia.
And lastly, a word of caution to those who take antihistamines and plan to drive while abroad. A recent study of over-the-counter antihistamines revealed that typical doses can impair driving ability in the same way that being legally drunk can. The researchers said that individuals vary greatly in their sensitivity to the drugs. Diphenhydramine and tripolidine were two of the drugs tested that were found to impair driving ability.