Allergy Causes

Introduction

The term allergy refers to an exaggerated response or reaction of immune to the substances that are generally not harmful. In fact we don't start out with allergies, but become allergic as a result of contact with the things which cause it. Allergy is immunity gone wrong. All of us need immunity to protect us from infections, and without our immune systems we would soon die from infection. A very important group of infections throughout human history has been infections from the parasitic worms. Even today, worm parasites cause vast numbers of deaths in poorer countries. But even when we have got rid of the worms from our surroundings we still have the same genes which protected us from this scourge. When we get allergies like hay fever or allergy to nuts, what happens is that this unused part of our immune systems is causing the mischief.

The word "allergy" has been used in two senses, firstly to mean an illness produced by a reaction of our immune system to some protein or other substance. The most common ones are hay fever, allergic asthma, food allergy, drug allergy, and infantile eczema. Secondly scientists use the word "allergy" to mean any kind of altered state of the immune system in which it reacts differently to a substance as a result of previous contact. To refer to illnesses brought on in this way, they use the expression "allergic disease". There are other ways in which our immune systems can cause allergic diseases. But it is still 'immunity gone wrong.

Causes

Allergy is usually the result of an oversensitive immune system, which leads to a misdirected immune response. The immune system normally protects the body against harmful substances, such as bacteria and viruses. In contrast, an allergic reaction is when the immune system reacts to substances that are generally harmless and in most people do not cause an immune response. In a person with allergies, the first exposure to the allergen triggers the immune system to recognize the substance. Any exposure after that will usually result in symptoms. Symptoms vary in severity from person to person. Most people have symptoms that cause discomfort without being life-threatening. Your body's overreaction to the allergens is what causes symptoms.

Pollen from the trees, grass and weeds: Allergies that occur in the spring are often due to tree pollen. Allergies that occur in the summer are often due to grass pollen. Allergies that occur in the fall are often due to ragweed.

Mold: Mold is common where water tends to collect, such as shower curtains, window moldings and damp basements. It can also be found in rotting logs, hay, mulches, commercial peat moss, compost piles and leaf litter. This allergy is usually worse during humid and rainy weather.

Animal dander: Proteins found in the skin, saliva, and urine of furry pets such as cats and dogs are allergens. You can be exposed to dander when handling an animal or from house dust that contains dander.

Dust: Many allergens, including dust mites, are in dust. Dust mites are tiny living creatures found in bedding, mattresses, carpeting and upholstered furniture. They live on dead skin cells and other things found in house dust.