An allergy is a reaction of your immune system to something that does not bother most other people. People who have allergies often are sensitive to more than one thing. Substances that often cause reactions are

Pollen
Dust mites
Mold spores
Pet dander
Food
Insect stings
Medicines

How do you get allergies?

Scientists think both genes and the environment have something to do with it. Normally, your immune system fights germs. It is your body's defense system. In most allergic reactions, however, it is responding to a false alarm.

Allergies can cause a runny nose, sneezing, itching, rashes, swelling or asthma. Symptoms vary. Although allergies can make you feel bad, they usually won't kill you. However, a severe reaction called anaphylaxis is life-threatening

As most people spend nearly half their waking lives at work, their work environment will be a major source of contact with possible allergenic substances. 

People eating wheat flour products and suffering allergy symptoms. Allergy problems can also result from the handling of wheat by farm workers and contact with wheat flour, by mill and bakery workers. In the former case, it is thought that concentrations of grain dust and fungal spores affected farm workers. A study of sixteen farmers in the United  Kingdom revealed that one quarter of farm workers in dusty, grain storage areas suffered from asthma. Sensitization usually occurred after several years although sometimes it took as long as ten to twelve years for the symptoms to develop. In the case of millers and bakers it was found that reactions were due to a mite known as acarus jarinae or more commonly, as the 'flour mite'. Allergy to this mite causes severe skin reaction. Further reaction to flour causing urticaria as well as nasal and bronchial symptoms, is thought to be due to the various chemicals added to the flour during the milling process to whiten it and preserve it. 

Allergies due to contact with work-related substances are plentiful. Over eight hundred substances have been listed as contact allergens. They include rubber, dyes, paints, cosmetics, medicines, epoxy resins, chrome and nickel. In a study of workers, exposed to proteolytic enzymes, in a Sydney soap factory, it was found that some workers developed rashes and severe itching of the skin. Other symptoms such as itchy eyes, swollen runny nose and hay fever persisted. Some also developed a dry, hacking cough and others, asthma. Enzymes in the soap industry have long been known to cause allergies. As a result, protective measures have reduced the problem, but the fact remains that some people cannot work in that industry. Researchers at Sydney University have found that proteolytic enzymes occurring naturally in grass thatch cause chronic lung disorders amongst New Guinea tribesmen. 

Other forms of contact allergy are to be found constantly throughout commerce and industry. Allergies to printers' ink, coffee dust, platinum salts (used in the photographic industry) and pharmaceutical drugs are just some further examples of this wide-ranging problem.