Allergic rhinitis is the most common of all childhood allergies. It causes runny, itchy nose, sneezing, postnasal drip and nasal congestion (blockage). The child with allergies may also have itchy, watery and red eyes and chronic ear problems. Despite its common name, “hay fever”, these allergy problems can occur at any time of the year – seasonally or year-round, and do not cause fever.
Allergies are the most common cause of chronic nasal congestion in children. Sometimes a child’s nose is congested (blocked) to the point that he or she breathes through the mouth, especially while sleeping. This may also cause the child not to get a restful night sleep and then be tired the next day. If the congestion and mouth breathing are left untreated, they can cause abnormal changes the way the teeth and the bones of the face grow. Early treatment of the allergies causing the nasal congestion may prevent these problems.
Some allergic reactions may cause only minor distress, such as a runny nose or itchy eyes, while others may result in life-threatening conditions, such as an asthma attack or anaphylactic shock. Anaphylactic shock is a severe and often life-threatening allergic reaction. It can be triggered by bee or other insect stings or bites, certain drugs or foods, dyes used in diagnostic tests, or even a blood transfusion. Shock occurs when the allergic reaction triggers the blood vessels to dilate, causing circulatory failure and a drastic drop in blood pressure. Swelling of tissues in the throat may result in a blocked air passageway. Loss of consciousness may follow. Like other allergic reactions, anaphylaxis does not occur upon the first exposure to an allergen but only after prior sensitization.
Determining the cause of an allergic reaction often takes time and patience. Tests usually involve trial and error to see if a given possible allergen triggers a reaction. In a skin test, small amounts of a suspected allergen are placed on the skin of the upper arm or back. Either the skin is scratched to allow entry of the allergen or the allergen is injected. Swelling and redness at the test site are considered a positive result. Several allergens are usually tested at the same time. Skin tests have a wide margin of error, however. They are most reliable for airborne allergens. The Radioallergosorbent Test (RAST) measures the amounts of specific IgE antibodies in the bloodstream. The results are not immediately available.
If a food allergy is suspected, one food for a time is eliminated from the diet and then added back to determine if it is triggering an allergic reaction. Antihistamines are the drugs most often used to control symptoms of allergic reactions. A shot of epinephrine is given in the case of anaphylactic shock, and anti-inflammatory drugs are given in the case of an asthma attack. The most effective treatment is avoiding the allergen altogether. Allergy shots, or immunotherapy, can be administered to eliminate the allergy entirely. In immunotherapy, a small amount of an allergen is injected in order to stimulate the body to produce an antibody to neutralize it. This, in turn, blocks the IgE antibodies from reacting with the allergen and provoking the allergic response. The allergies for which shots are most effective include pollen, mould, insect bites, and animal hair.