Allergic rhinitis (also called hay fever) is the most common form of allergy to the environment. Allergy symptoms often vary with the seasons.
SIGNS AND SYMPTOMS OF ENVIRONMENTAL ALLERGIES
- Stuffy, runny nose
- Itchy nose, eyes, and throat
- "Sinus" symptoms—headache, feeling of pressure behind the eye, pain above the cheekbones and on the lower forehead, aching teeth
- Skin rashes or hives
- Diarrhoea or frequent urination
CULPRITS FOR ENVIRONMENTAL ALLERGY
- Pollens, grasses, or ragweed (in certain seasons and areas)
- Dust and household mites
- Changes in temperature or humidity
- Spicy foods
- Smoking or prolonged exposure to second-hand smoke
Food and environmental allergies are known to cause the following illnesses:
WHAT HAPPENS DURING AN ALLERGIC REACTION?
When a person with a hyper-alert immune system is exposed to an allergen, a series of events takes place:
- The body starts to produce a specific type of antibody, called IgE, to fight the allergen
- The antibodies attach to a form of blood cell called a mast cell. Mast cells are plentiful in the airways and in the GI tract where allergens tend to enter the body
- The mast cells explode releasing a variety of chemicals including histamine, which causes most of the symptoms of an allergy, including itchiness or runny nose
- If the allergen is in the air, the allergic reaction will likely occur in the eyes, nose and lungs. If the allergen is ingested, the allergic reaction often occurs in the mouth, stomach and intestines. Sometimes enough chemicals are released from the mast cells to cause a reaction throughout the body, such as hives, decreased blood pressure, shock, or loss of consciousness
SYMPTOMS OF ENVIRONMENTAL ALLERGY
Allergy symptoms can be categorized as mild, moderate, or severe (anaphylactic).
- Mild reactions include those symptoms that affect a specific area of the body such as a rash, 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. These may include itchiness or difficulty breathing.
- A severe reaction, called anaphylaxis, is a rare, life-threatening emergency in which the response to the allergen is intense and affects the whole body. It may begin with the sudden onset of itching of the eyes or face and progress within minutes to more serious symptoms, including abdominal pain, cramps, vomiting, and diarrhea, as well as varying degrees of swellings that can make breathing and swallowing difficult. Mental confusion or dizziness may also be symptoms, since anaphylaxis causes a quick drop in blood pressure.
DOES EVERYONE HAVE ALLERGIES?
NO. Most allergies are inherited, which means they are passed on to children by their parents. People inherit a tendency to be allergic, although not to any specific allergen. When one parent is allergic, their child has a 50% chance of having allergies. That risk jumps to 75% if both parents have allergies.