Allergy

Allergy is  an abnormal response of the immune system. People who have allergies have an immune system that reacts to a usually harmless substance in the environment. This substance (pollen, mold, animal dander, etc.) is called an allergen.

Allergies are a very common problem, affecting at least two out of every 10 Americans.

Common symptoms of an allergic reaction include itchy, watery eyes, sneezing, itchy, runny nose, rashes, feeling tired or ill, hives, stomach cramps, vomiting, or diarrhea.

The severity of the allergic reaction’s symptoms can vary widely:

• Mild symptoms may be almost unnoticeable, just making you feel a little “off.”
• Moderate symptoms can make you feel ill, as if you’ve got a cold or even the flu.
• Severe allergic reactions are extremely uncomfortable, even incapacitating.

Most symptoms of an allergic reaction go away shortly after the exposure stops.

The most severe allergic reaction is called anaphylaxis. In anaphylaxis, allergens cause a whole-body allergic reaction that can include:

• Hives and itching all over (not just in the exposed area)
• Wheezing or shortness of breath
• Hoarseness or tightness in the throat
• Tingling in the hands, feet, lips, or scalp

Anaphylaxis is life-threatening and requires immediate medical attention. Symptoms can progress rapidly, so head for the emergency room if there’s any suspicion of anaphylaxis.

Not everyone has allergies. 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.