In the next few months millions of Americans will start sneezing, wheezing, scratching, rubbing their eyes and honking their noses. It's the allergy season. But allergy in fact is not just a summer affliction, as anyone can testify who suffers from asthma, eczema, sensitivity to bee stings or even to the metal in jewelry. An expert in the field is Dr. Sheldon Cohen, who has studied, taught and researched allergy and immunology for nearly 30 years. As chief of the Allergy and Immunology Branch of the National Institute of Allergy and Infectious Diseases, Dr. Cohen administers a research budget of nearly $33.5 million a year. Recently the 57-year-old bachelor scientist discussed the subject with Barnard Collier for PEOPLE.

What should make people suspect that they have an allergy?

Let's assume they have redness of the eyes and tearing, nasal discharge, sneezing, cough, shortness of breath or wheezing or a skin eruption that is persistent, current and periodic. Especially if these symptoms relate to seasonal factors or exposure to particular substances, they are probably allergic in origin.

Does air pollution create allergies?

Pollen creates hay fever allergy. Pollen is in the air at one time or another in most of the world and is a kind of natural pollution. On the other hand, the air sometimes contains a chemical mist, often sulfur fumes from factories. Combined with moisture, the fumes form sulfuric acid droplets, which may make your eyes run the way hay fever does, your lungs hurt, your nose itch. But you aren't allergic to sulfuric acid the same as you are to pollen. The body reacts to pollen by trying to fight it off. Sulfuric acid droplets simply burn the flesh. Such chemical pollutants irritate everyone universally; pollen in natural amounts does not affect everyone.

What can be done to relieve hay fever?

An air conditioner will filter out pollen almost entirely. People without air conditioners can tack wet sheets over their windows. Drugstores sell effective face masks. An electric dust attractor can pull dust and pollen out of the air. And there is always the desert, which has a low pollen count all year round.

What is the most allergy-producing substance?

I'd say house dust, year round. It is full of wool bits, feathers, mohair and cat and dog dander, the scraped-off pieces of their skin. Animal allergy, incidentally, is usually serious and irreversible—a person allergic to cats is allergic to them for life.

What medicines are available for allergic asthma sufferers?

Adrenaline and similar chemicals have been used for years to relax lung muscle spasms and make breathing easier. There's a newer drug called theophylline, which is close to caffeine. It was known that drinking huge amounts of coffee was helpful for asthmatics. Another new drug, cromolyn sodium, was said to be almost 100 percent effective in countering attacks in England, but here it is proving to be about 40 percent effective.

What about antihistamines and cortisone?

Antihistamines block the irritating effect of histamines, body chemicals released into the blood from allergy-producing cells. The drug attaches to normal cells and prevents them from being hurt by the histamines. An antihistamine relieves swelling and makes you sleepy. Cortisone, the hormone produced by the adrenal gland, and similar synthetic drugs reduce the inflammation of an allergic reaction. Which drug to use is a matter for doctors to decide.

How do you prevent poison ivy itch?

Stay away from it. Almost anybody whose skin comes in contact with the oil in poison ivy is going to suffer some degree of allergic reaction after the first exposure. A minimum of one exposure is necessary to create sensitivity. It may take two or more exposures.

Why the second time, and not the first?

The first time the body encounters the oil, called urushiol, it sends out cells to engage the intruder and fight it off. These cells remember what the intruder looks like and pass the information along to other cells. The next time the intruder shows up, the body sends in its defenses.

How are we aware of the battle?

The cells with memory, called lymphocytes, migrate to the spot. They secrete chemicals which immobilize other cells, causing the area to inflame. This results in redness, swelling and itching. It is nature's way of responding, but nature has played a dirty trick. The hypersensitive reaction is anywhere from mildly annoying to severely disabling.

What can we do about the awful itching?

You can try home remedies or find others in the drugstore to relieve itching. But you may be allergic to them. Hot water is effective because it deadens the nerve endings temporarily. But applied to a skin rash or blisters, it can cause increased inflammation and make matters worse.

Does scratching spread poison ivy?

That's a myth. The blisters do not contain any more of the urushiol oil. But you might cause a secondary infection by breaking the skin.

Are people ever allergic to the sun?

Maybe. Sometimes people are allergic or sensitive to the sun because it reacts to a drug on the skin. One of the most common drugs which can cause this allergic reaction is para-aminobenzoic acid, used in certain suntan preparations. You can also become sensitized by additives in cosmetics, perfumes, sulfa and tetracycline-type drugs. The ultraviolet rays of the sun react with the drugs on or in the skin, to form new chemicals to which the body becomes hypersensitive.

What are other common allergy producers?

A woman with dyed black hair itches and gets red around the face and scalp; she may be allergic to an ingredient in the dye. There is a rash around a little girl's wrist caused by the nickel in the costume bracelet she wears. A woman is red and itchy around her girdle and bra straps—and it may be a chemical in the rubber. In California, allergy to poison oak is the number one industrial disease among agricultural field workers.

Are there any new developments in allergy testing?

Besides the patch test on the surface of the skin and test injections, a procedure called the "broncho-provocation" test is being experimented with. The patient inhales a measured dose of air and mist containing a suspected substance, such as extract of ragweed. The patient then blows as hard as possible into a machine that measures air pressure in the lungs. If the patient has inhaled something that produces an allergic reaction, the amount of air he can exhale is greatly reduced. The effect is almost instantaneous. At present, the machine is the most sophisticated way to distinguish allergic asthma from bronchitis or emphysema.

What kinds of allergies may be fatal?

I've never actually seen anyone die from penicillin allergy. I've always gotten there too late, because they are dead in five or 10 minutes. I've seen people almost dead of bee stings. This kind of fast, overwhelming allergy produces a dramatic plunge in blood pressure, unconsciousness and profound shock. Unless someone is around to inject adrenalin into them, they may die in moments.

Must people be afraid of bees, then?

People who are demonstrably allergic to bees should avoid them completely. There are 30 to 40 deaths every year from bee, wasp and hornet venom. A small amount of immunizing agent is made from bee venom. But imagine how hard it is to collect the venom! Still, one researcher has found a way to get bees to sting through stretched rubber.

Can people be allergic to themselves?

Yes. And it's not uncommon. Your own body tissue can change so that it becomes foreign to you. Lupus is a disease where you become sensitive to the protein in your own blood cells. We will hear more and more about lupus diseases in the future, almost as much as about arthritis today. It is also possible that diabetes, hyperthyroid disease, pernicious anemia and possibly ulcerative colitis may be allergic diseases. We are just now opening up a whole new area of understanding.