Allergies

What is „ Allergy"?

An allergy is the reaction of the immune system towards a particular substance, which is hence referred to as allergen. A person can be non-allergic towards a substance, whereas others react in different ways. A runny nose, itchy eyes, palate or a skin rash are all signs of the bodies allergic reaction towards the substance. It aggravates the sense of smell, sight, taste and touch, causing irritation, extreme disability and sometimes fatality. The most common allergies are hay fever, house dust mite and pet allergy as well as allergic asthma and neurodermatitis.

Allergy is a widely spread disease, effecting approximately one out of four UK citizens. Every year these numbers increase by 5% with half of this amount being children. Allergic diseases are more common in industrialized countries compared to countries following a more traditional or agricultural lifestyle.

What is the cause of an allergic reaction?

Almost anything could trigger an allergic reaction. The most common allergens are: tree and grass pollen and, house dust mite, animal hair such as cat and dog hair, insects like wasps and bees, industrial and household chemicals, drugs and foods such as milk and eggs. Less common allergens include nuts, fruit and latex.

The aim of the immune system is to mobilize its forces at the site of invasion and destroy the enemy. One of its ways is to create protective proteins called antibodies that are specifically targeted on particular foreign substances. Once a person is exposed to one of the aforementioned substances, the foreign substance, the body's immune system gets ready to fight them. White blood cells (B-lymphocytes) produce an antibody (immunoglobulin E, IgE) against the allergen. IgE is the special allergic antibody. It sticks to the surface of the allergy cells. Now the body is ready to fight back the next time it is exposed to the allergen. This process is called sensitization. IgE is an antibody that all of us have in small amounts. Allergic persons, however, produce IgE in large quantities.

After this sensitization there is an allergic reaction every time the body is exposed to the allergen. The allergen sticks to the antibodies on the surface of the allergy cells. This coupling causes the granula (little stores in the allergy cells) to release histamine, which causes the allergic symptoms. The histamine dilates the blood vessels, causing the mucous membranes to swell and stimulate the glands in the nose and the respiratory passages to produce mucus.

Symptoms

Certain body parts are prone to react to allergies. These include eyes, nose, lungs, skin and stomach. Although the various allergic diseases result in different reactions, they all derive from an exaggerated immune response to foreign substances in sensitive people.

Common symptoms of Allergy (Source: wikipedia)

Nose:                                    swelling of the nasal mucosa (allergic rhinitis)

Sinuses:                                 Allergic sinusitis

Eyes:                                      redness and itching of the conjunctiva (allergic conjunctivitis)

Airways:                                Sneezing, coughing, bronchoconstriction, wheezing and dyspnea, sometimes outright attacks of asthma,  in severe          cases the airway constricts due to swelling known as angioedema

Ears:                                        feeling of fullness, possibly pain, and impaired hearing due to the lack of eustachian tube drainage

Skin:                                        rashes, such as eczema and hives (urticaria)

Gastrointestinal tract:   abdominal pain, bloating, vomiting, Diarrhea

Depending on the time and amount of the allergens exposure and where the body-contact takes place, there will be an allergic reaction in the form of hay fever (allergic rhinitis), asthma, allergic eyes, allergic eczema, hives or allergic shock.

• Hay fever/ allergic rhinitis: this most common allergic disease stands out with seasonal nasal symptoms that are due to pollens.
• Allergic asthma: a breathing problem that results from the inflammation and spasm of the lung's air passages (see content "Asthma").
• Allergic eyes/ allergic conjunctivitis: an inflammation of the tissue layers that cover the surface of the eyeball and the undersurface of the eyelid.
• Allergic eczema/ atopic dermatitis: an allergic rash that is usually associated with allergic rhinitis or asthma and not caused by skin contact with an allergen.
• Hives/ urticaria: skin reactions that appear as itchy swellings on any part of the body.
• Allergic shock/ anaphylaxis: a severe, whole body and life-threatening allergic reaction that can affect a number of organs simultaneously.

Treatment

The traditional treating method of allergies is to simply avoid the particular allergen or to at least reduce contact. While avoidance may help to reduce symptoms and avoid life-threatening anaphylaxis, this may seem challenging in the case of allergies towards air-borne allergies such as pollen. Strict avoidance still plays a role in coming to terms with ones allergy and is especially helpful in cases of food allergies.

Besides that, medication on treating allergic conditions has vastly improved.