National Allergy Day
Proclamation 978 was signed by former President Gloria Macapagal-Arroyo on Jan. 30, 2006 declaring July 8 as National Allergy Day.
Studies have shown the Philippines has high prevalence rates of allergies like rhinitis and asthma. The medical cost of treating allergic symptoms continues to increase.
What is allergy?
An allergy or hypersensitivity reaction occurs when a person’s normal body tissue is injured by reactions of his immune system to an antigen or allergen. Antibodies of the immunoglobulin E or IgE class bind to white blood cells called basophils in the blood and to mast cells in tissues. When an allergen is encountered, these cells release histamine and other chemicals that cause inflammation and tissue injury.
The following are the manifestations or signs and symptoms:
Hivesor urticaria – itchy patches on the skin;
Puffiness or swelling of the face, eyelids, ears, mouth, hands, or feet;
Watery, itchy eyes; dizziness; passing out or fainting;
Vomiting or loose bowel movement; itching or redness of the skin; runny nose (rhinitis), sneezing; swelling of the tongue;
Wheezing or difficulty in breathing; and rare but it can happen – in severe allergy, death from lack of oxygen when a person’s airways become swollen (anaphylaxis).
Why is knowledge and awareness about allergy important?
One cannot change his or her genes, so one with hypersensitivity reactions already has a “built-in” reaction to a specific allergen. Avoidance of a known allergen is the key to the prevention of a hypersensitivity reaction.
Having a ready list of one’s known allergens prevents discomfort and can be life-saving. Common food allergens are milk, eggs, shellfish, nuts, wheat, soybeans, and chocolate. Other allergens include animal dander, bee sting, food coloring, dust mites, pollens, and drugs.
Anaphylaxis can occur in a sensitive person soon after consuming certain foods or taking certain medications, usually within two hours after exposure.
The allergen enters the blood and reacts with IgE antibodies. In this situation, the person becomes agitated, uneasy, has tingling sensations, itchy and flushed skin, coughing, and sneezing. Swelling of the airway leads to shortness of breath. Blood vessels dilate and the low blood pressure drops, leading to cardiovascular collapse.
Anaphylaxis happens in a person with previous exposure to an allergen – the person has been previously “sensitized” to the allergen, hence his immune system readily recognizes it and rapidly produces antibodies.
Skin tests combined with history of allergy or allergen challenge help identify a person’s allergens. Skin tests are not routinely done in patients with history of anaphylaxis, are taking medications that may interfere with the treatment of anaphylaxis, or have certain skin conditions like acute or chronic urticaria that make interpretation of skin tests difficult. Skin tests are also not routinely performed in patients with poorly controlled asthma and reduced lung function.
Management of allergies includes the following:
Avoidance of known allergens;
Desensitization by eating small amounts of a food may be tried but may not always be effective. Precautions should be taken because some persons can develop severe allergic reaction even to small amount of allergen;
Antihistamines can be useful for acute reactions like hives;
Long-term allergen immunotherapy or AIT-based on a country’s guidelines;
Epinephrine injection for anaphylactic reaction; and
Chinese herbal medicines like antiasthma herbal medicine intervention or ASHMI formula, which contains three Chinese herbs, modified MMDT formula, and other preparations that are currently being evaluated.
Medical questions or suggestions may be emailed to [email protected] or [email protected]