An allergy is characterized as an immune reaction to the presence of certain substances in one’s body. Allergies occur when the immune system mistakes a harmless substance for a pathogen. The immuniglobin responsible for allergies is the IgE immuniglobin. Humans are not born with IgE antibodies in their body. The IgE develops 10 days after the first exposure to allergens. Therefore, it takes repeated exposure to an allergen, to develop an allergy. Allergies are often not formed upon first exposure.

Have you ever wondered why people have specific allergies? This is because IgE immuniglobins have a single protein structure and a set of molecules that all have a slightly different structure. The IgE, for example that reacts with pollen, is not the same IgE that will react with dust. People who have allergic reactions, also have more IgE present in their bodies than the average, non-allergy containing person. For example: people with hay fever have about 14 times as much IgE as those who do not.

There are four basic ways that allergens can enter human bodies: inhaling, touching, ingestion or by injection. There are also two basic types of allergic reactions known as: immediate or delayed. In a delayed allergic reaction, symptoms usually appear about 4 hours, to a few days after exposure to an allergen. In an immediate reaction, symptoms usually appear only minutes after exposure.

The chemical that is associated with the symptoms of allergy such as itching or swelling, is called Histamine. Histamine is the main chemical involved in allergies. Histamine is formed from the breakdown of Histine, which is an amino acid. Histamine causes many things that lead to the symptoms experienced during an allergic reaction. Histamine, for example, can cause contraction or swelling of certain muscles, or stimulate the production of tears or saliva. It can also cause blood vessels to become dilated, which leads to swelling. The most severe reaction relating to histamine is known as anaphylactic shock. This occurs when an allergy causes a significant drop in blood pressure, and can result in death.

There are chemical treatments that are used to treat allergies. Some of these treatments include: steroids and antihistamines. Antihistamines are the most commonly distributed chemical treatment for allergies. Antihistamines simply block histamines from certain sites on cells, which prevents the allergic reaction caused by histamines from occurring. There are very many antihistamine medications that affect people in different ways. That is why it is best to consult a doctor about the one best suited to your specific body type and allergy. Steroids work to relieve swelling, itching and redness that occurs as a result of an allergic reaction. Therefore, steroids are often used on allergy symptoms such as hives or eczema.