Allergies occur when the body's immune system reacts to non-harmful substances in the environment.
Different people suffering from allergies react differently when exposed to the substance they are allergic to. Some of the most common reactions and diseases include:
The most common type of eczema is atopic dermatitis. Skin is often rough, hard, prone to cracking, low-pigment and itchy.
Urticaria (commonly known as hives) is a kind of skin rash notable for raised, well-defined rash and bumps, which are usually very itchy.
Allergic rhinitis is often accompanied by allergic conjunctivitis, since the eye is also in constant contact with substances found in the air. The common symptoms of inflammations caused by allergies are red eye, soreness and itching sensations, as well as watery eyes. Subjective symptoms include itching, burning sensations, feeling that a foreign body is in the eye and, sometimes, photosensitivity.
Allergic rhinitis is an inflammation of nasal airways, i.e. upper respiratory tract. The most common symptoms are the feeling of nasal congestion, mucus production, sneezing and itching.
Asthma is an allergic disease of the lower respiratory tract. Its symptoms include heavy breathing or breathlessness, a feeling of "wheezing" and cough - both dry and productive, when the patient produces phlegm or mucus.
Anaphylaxis or anaphylactic shock is a reaction of the whole body, which leads to heavy breathing, as well as a sudden drop in the blood pressure, occasionally even a loss of consciousness. This is the most dangerous and most dramatic allergic reaction that may even result in death.