The driver of the cab I hired in Chicago told me that he was allergic to his new girlfriend. He didn’t know what it was about her, but he broke out whenever he got near her. He was certain it wasn’t anything obvious like perfume or cosmetics. Farfetched? Not at all. A few days later, I stumbled across a possible explanation.

An allergist in that same city told me that sensitivity to human dander – hair and skin particles – has been written about in medical journals from time to time. Of course, I never did find out how the cabbie fared. But his was just one of several types of odd allergies that I ran across while researching – allergies which I’ll review here in case your or someone you know happens to have a very unusual problem.

Some of these allergies are so rare that doctors have had little opportunity to develop any real therapy – other than to avoid the cause of the problem (unless it's something you’re willing to endure – like your girlfriend).

Sunlight

Allergy to sun light may sound like the ultimate in hypochondria. But it does occur. And not only in people who are taking certain drugs or handling chemicals that activate skin problems in the presence of light. Once in a blue moon (or sun), along comes someone who really is allergic to light per se – and the only certain wavelengths: artificial light or light streaming through a window is okay, but direct light is a problem.

The person’s skin gets red, swollen and tender, except for well defined areas covered by sleeves, trousers or a hat – just like sunburn. But the skin flares up only moments after an exposure too brief to produce sunburn in most people. Sometimes the mock burn is accompanied by headaches, vomiting and burning eyes.

Very rarely, light sensitivity can lead to anaphylactic shock. People with allergy to sunlight don't go to many beach parties. But they don't have to go underground, either. Protective clothing is a must, of course. And sunscreens can be a tremendous help. Mildly sensitive people can build up their tolerance to sunlight by exposing small areas, a little at a time.

Cold Temperature

Some people break out in hives when they dash in and out of an air conditioned store in summer. Or when they come into a warm house after shoveling snow. Or if they make a quick dip in chilly pond or pool. Or even if their hands in cold water.

That’s called cold urticaria, and while it's the drop in temperature that triggers the reaction, the symptoms appear as the body temperature warms up again. That increase in body temperature, it's believed, release histamine and other allergy triggering body substances (explained in Understanding Allergy).

Hives may develop all over the body, but they're usually more prominent in the areas directly affected by the cold, such as uncovered hands or face. If even cold foods is eaten, the lips and tongue may swell somewhat. And cold induced hives may be accompanied by headache, vomiting, rapid heartbeat and fainting.

Cold urticaria is related to allergy to exercise, which also prompts a rise in body temperature, and is medically referred to as a ”cholinergic” allergy, which means that the allergy involves the nervous system. And cold allergy can be accompanied by water allergy, a rare and slightly different variation of cholinergic allergy.

It's not always easy to tell the difference between cold urticaria, exercise urticaria or water urticaria. Widespread hives that develop after swimming, for example, could be caused by cold water, exertion (if it's a heated pool) or by the water itself. To sort it out, doctors do what amounts to a patch test with an ice cube. If you don't react, you’re not cold sensitive.

Allergy to cold temperature is very often part of one of a few other, underlying illness, and disappears when the disease is cured. In other cases, cold allergy subsides as mysteriously as it began. If not, common sense tells the individual to take precautions against exposure to cold.

Where cold is unavoidance for the allergy is a major problem, many people have been successfully desensitized to cold temperature by gradual exposure to decreasing temperatures – either in a cold room or cold water – for progressively longer periods of time until cold room or cold water – for progressively longer periods of time until cold can be tolerated.

If that doesn’t work, antihistamine may help. While we don't encourage casual use of drugs, we do feel that in certain circumstances – such as this – medication is less of hazard than the risk of a severe reaction to an unavoidable allergen (for more on medical therapy, see Allergy Drugs and Their Alternatives).

Exercise

”Allergy to exercise” may sound like a lame excuse to stay chair bound. But there actually are a few rare individuals who swell up and break out in hives after mild exertion. A couple of laps across the pool or a few minutes of jogging leave them not only red and itchy, but possibly even dizzy, nauseated and exhausted.

In most cases, antihistamine can help. Asthma attack, too, may be trigger by strenuous exertion. But those breathing difficulties may be due to the direct effect of cold, dry air on sensitive airways and are in no way related to exercise induced hives.

Water

Water allergy (aquagenic urticaria) is rare. Only 12 cases have been reported. Water of any temperature touches off itching and spotty hives. And like allergy to cold or emotional triggers, histamine release seems the basic mechanism at work. In one of the few cases studied, oral doses of hydroxyzine (an antihistamine) three time a day for one week effectively blocked the reaction to water.

Emotions

As a school girl in Sweden, actress Ingrid Bergman who so shy that she used to break out when she had to recite in class. Her fingers swelled so badly she couldn’t bend them. Her lips and eyelids swelled, too. The doctor said Ingrid was allergic to shyness. Fortuneless for Ingrid and the film world, drama school eventually cured her.

But her case is good example of how we can be allergic to strong emotions. Emotionally stimulated allergy may be triggered not only by shyness, but also anxiety, anger, fear, embarrassment – any emotion that prompts an increase in body temperature.

Sperm

A few women have been surprised to learn that they're suddenly become allergic to their partner’s sperm. One woman experienced anaphylaxis while having sex with her husband – an extraordinary response by anyone’s standards. Skin test confirmed that her husband’s sperm was provoking allergic antibodies.

The woman’s doctors were able to desensitize her in much the same way they desensitize other individuals against pollen. She and her husband were able to resume their love life safely (Journal and Clinical Immunology, abstract no.182, January, 1982).

Condoms

Snicker if you will, but dermatitis from condoms isn’t all that rare. A reaction usually begins with a swelling of the foreskin, which may spread to the shaft, scrotum and inner thighs. In most men, the allergy is to rubber – in which case they're probably had other unpleasant brushes with rubber in clothing or other articles.

Switching to another brand of condom may help. ”Some man have found by trial and error that only certain brands of rubber condoms produced reactions, while others were well tolerated,” writes Alexander A. Fisher, M.D. (Contact Dermatitis, Lea and Febiger, 1978).

Occasionally, the problem isn’t the rubber itself but a powder or lubricant it bears. Try a plain, untreated product. Otherwise, some rubber sensitive men may have to switch to the original, old fashioned condoms made from sheep’s intestine (such as Fourex, by Schmid Products, or Natural lambskin, by Young Drug Products).

And of course, a partner’s condom should be suspected as a possible cause of an unexplained rash or other inflammation on the vulva or inner tights of a woman, even if her partner isn’t allergic to the device.

Spermicides

Allergy to vaginal spermicides (sperm killing creams, foams or jellies) isn’t common, but it happens nevertheless. The four most sensitizing chemicals in these products are phenylmercuric acetate, oxyquinoline sulfate, quinine hydrochloride and hexylresorcinol.

If a woman’s choose spermicide is making her itch or giving her other discomfort, she should look for an alternative with different ingredients. Before using a brand or type of spermicide for the first time, she can do a patch test on her arm to determine her tolerance. As with condoms, what’s good for the goose may be bad for the gander: a woman’s partner is also apt to react to contact with vaginal spermicides, even if she doesn’t.

Feminine Hygiene Sprays

Aside from the fact that these sprays do little or nothing for vaginal hygiene, they may irritate and produce a burning sensation if squirted too close to the skin or vulva. Applied from a proper distance, the freon propellant presumably evaporates before it reaches it's destination.

Even then, the perfumes can cause trouble. And a woman’s partner may develop a rash or burning sensation on his penis or scrotum if they have sex together soon after the spray is applied. So why bother with sprays at all?

Copper I.U.D.s

Copper containing intrauterine birth control device sometimes induce stubborn allergic reaction in women who use them. The classic symptoms are recurrent rash on and around the vulva, lower abdomen and inner thighs. Less frequently, it may spread to the chest and lower back.

Ointments, antihistamines and cortisone treatments provide only temporary relief. The only real cure is to have the I.U.D. removed and choose an alternative birth control methods.