With the increasing use of condoms to prevent the spread of AIDS and other sexually transmissible diseases and with the increased use of latex surgical gloves for the routine physical examinations of patients, there has been an alarming rise in the incidence of allergic reactions to latex rubber. In other words, because of increased exposure to latex products, more people are becoming allergic to it than ever before.

At present between 1 percent and 2 percent of the population is allergic to latex rubber, and as many as 10 percent of all health-care workers (that is, physicians, dentists, nurses, and so forth) are now latex-sensitized. Allergic contact rashes on the hands are the most common manifestation, but, though rare, shock and even death from immediate hypersensitive allergy have been reported. By itself, natural rubber is almost never a sensitizer; rather, the culprits are the many different chemicals that go in to the vulcanization and manufacture of rubber products. These include residual latex proteins, mercaptoben-zothiazole (MBT), and thiurams.

Fortunately, while other substitutes are being actively sought, a number of alternatives to latex have been available for some time. For example, garments containing spandex, a synthetic elastic fiber, have been around for a number of years and can be recognized by the manufacturer's names. And industrial-strength synthetic rubber gloves made of neoprene have also been available for a while.

Likewise, sexually active persons with latex allergies may currently turn to styrene or polymer condoms for effective contraception and infection control. While the use of natural, skin-type condoms (made from sheep's intestine) would seem like a logical alternative when one partner, or both partners, is latex-sensitive, such condoms unfortunately do not provide adequate protection against transmissible sexual diseases. For the moment, then, the use of two types of condoms has been suggested in order to minimize allergic problems while ensuring both adequate contraception and disease prevention. If the sexually receptive individual is latex-allergic, the partner may-first apply a latex condom and then a natural condom over it before insertion. If the situation is reversed, however, and the user is allergic to latex, then the natural condom should be applied first and the latex one over it to prevent direct contact with his skin. Looking to the not-too-distant future, a woman's condom made of polyurethane plastic, which at this time is still under investigation by the Federal Drug Administration, will no doubt be welcomed by latex-sensitive couples.

Fortunately, health-care workers may also choose from several alternatives. To avoid the problem entirely, many choose to use disposable vinyl gloves whenever possible because they contain no rubber derivatives at all. But when greater dexterity is required, they may select Elastryn, a specially designed hypoallergic glove made of nonvulcanized rubber. Surgeons who require sterile, anatomically fit gloves may purchase products made of tactylon, a nonlatex, nonvulcanized synthetic copolymer (Tactyl) or those made from a group of fancy-sounding substances known as accelerated antibiodioxidants (specifically, Neolon and Dermaprene). Biogel gloves, a newcomer to the medical marketplace, claims to have virtually undetectable levels of allergenic latex proteins and extremely low levels of potentially allergenic rubber accelerators in both its sterile and nonsterile glove lines.

Keep in mind that not every allergy to rubber products is related to the latex protein itself. Allergy to examination gloves, for example, may be due to the powders or starches that coat the inside of them to absorb perspiration and to facilitate application and removal. In the case of condoms, allergies may be due to the preservatives in the wet jellies used to coat the lubricated varieties or, less commonly, to the sil-icone-based lubricants used in the dry varieties. If this is the case, simply changing the type of product you use may end the problem.

When suspected, dermatologists can test for latex allergy through a "use" test. In this test, a rubber glove or just the finger portions are worn on damp hands for between fifteen and thirty minutes and are then checked for the development of a rash. Alternatively, or in addition, the physician may cut a small square of latex and apply it as a patch test directly to the back or inner arm and evaluate it for allergic changes in forty-eight to seventy-two hours.

For most cases of rubber-induced rashes, treatment consists of a short course of topical steroid creams. Though rare, oral steroids may be needed to suppress the inflammation.

Much of what has just been said about poison ivy, nickel allergy, and latex contact allergy applies equally to all the many other substances found in your home or workplace that may trigger contact allergies. In order of frequency, these include: neomycin, which is found in many OTC topical antibiotic preparations; thimerosal, which is a preservative found in many topical and ophthalmic preparations such as contact lens solutions; formaldehyde, which is encountered in permanent press clothing and many other industrial products; quarternium IS, which is a common preservative ingredient and a formaldehyde-releasing chemical that is used widely in industry; paraphenylenediamine, which is the most common hair dye agent in use today; balsam of Peru, which is a popular fragrance; and cinnamic alcohol, which is a common aromatic and flavoring ingredient. Other well-known culprits may be found in certain cosmetics, clothing (wool, synthetic fibers, dyes, and leather), many kinds of household items (such as detergents, disinfectants, bleaches, polishes, and waxes), and numerous workplace items (cements, glues, plastics, and paints).

In the past few years, the use of skin patches for the delivery of medication, such as estrogen for menopausal symptoms and scopolamine for motion sickness, have become increasingly popular. At the same time, such transdermal delivery systems, as they are known medically, have also become responsible for a growing number of instances of allergic contact dermatitis. Transdermal clonidine, an antihypertensive agent, has so far accounted for the majority of allergic contact reactions. Curiously, most people who are unable to tolerate the clonidine patches are able to take the medication orally without any problem.

In most cases of allergic contact dermatitis, the history and the location of the condition provide strong clues to the diagnosis. As part of the workup, your doctor will usually question you in detail about your home routines, occupational activities, and hobbies, exploring possible exposure to cosmetics, plants, and topical medications, both OTC and physician-prescribed.

When allergic contact dermatitis is strongly suspected but no specific agent can be pinpointed definitively as the troublemaker, your doctor may suggest patch-testing on normal skin with a screening battery of allergens. A standard screening battery contains many of the allergens known to be used in the home and in industry. Once a particular allergen is identified by this method, the doctor can provide you with a list of specific products and items to avoid.