Allergies present themselves when your body mistakes a harmless substance for something dangerous, thus trying to rid itself of this danger. While your body attempts to excrete the allergen (foreign substance), it causes allergy-like symptoms. The first time your body reacts to an allergen, it does so by producing allergens. Each subsequent time it's exposed to that allergen, the body produces increased amounts of antibodies to that allergen, until the body eventually experiences the symptoms.

 How are allergies diagnosed?

If you think you have allergies, don’t wait to see if the symptoms will go away. When the symptoms last longer than a week or two and tend to recur, make an appointment with an allergy/immunology specialist so a complete evaluation can be performed.

Allergy skin testing may be used to identify the allergens that are causing your allergy symptoms. The test is performed by pricking your skin with an extract of an allergen, and then evaluating the skin’s reaction.

If a skin test cannot be performed, a radioallergosorbent blood test (RAST) may be taken, although its results are not as sensitive as a skin test. This RAST evaluates the number of antibodies produced by the immune system. Elevated levels of certain antibodies can identify particular allergies.

 What are the symptoms of allergies?

Mild reactions include local symptoms (affecting a specific area of the body) such as a rash or hives; itchy, watery eyes; and some congestion. Mild reactions do not spread to other parts of the body.

Moderate reactions include symptoms that spread to other parts of the body. Symptoms may include itchiness, hives, and swelling, that spreads or difficulty breathing.

A severe allergic reaction, known as anaphylaxis, is a rare, life-threatening emergency in which the body’s response to the allergen is sudden and affects the whole body (systemic).

Anaphylaxis may begin with severe itching of the eyes or face and. within minutes, progress to more serious symptoms, including throat swelling, abdominal pain, cramps, vomiting. Mental confusion or dizziness may also result, since anaphylaxis may cause a drop in blood pressure.