Allergy

Allergies are caused when your immune system responds to typically harmless substances (allergens) as though they were dangerous. The immune system protects your body from the things that make you sick, such as bacteria and viruses. However, if you have allergies, the immune system causes your body to react to allergens in the same way it would respond to a bacteria or virus - by trying to get rid of it. This is what results in an allergic reaction. Immune system cells respond to allergens by releasing chemicals, like histamine, that cause the blood vessels in your air passages to expand extra mucus to be produced resulting in the symptoms we associate with allergies.

There are two types of allergies — seasonal and perennial:

1. Seasonal allergies occur at specific times during the year and are triggered by outdoor allergens. Common seasonal allergens include:
   • Tree pollen — most common in April and May 
   • Grass pollen — most common in June and July 
   • Ragweed — most common in August and September
   • Outdoor molds – most common in late summer when fallen leaves begin to rot and the weather is damp
2. Perennial allergies are caused by indoor allergens and often get worse in the wintertime when you tend to be indoors more often although you can be affected year round. Common perennial allergens include:
   •  Dust and dust mites 
   • Indoor mold 
   • Animal dander 
   • Feathers 
   • House plants

The list of allergy symptoms is quite long and can read like a list of cold symptoms. With allergies, however, the symptoms are off and on and can last for weeks or months. The common cold will usually clear up in 7 to 10 days.

Allergy symptoms include:

• Red, itchy, watery eyes or conjunctivitis (inflammation of the membrane that lines your eyes)
• Sinus pain or sinusitis
• Stuffy nose
• Runny nose
• Itchy rash or hives
• Wheezing and coughing
• Sneezing
• Post nasal drip or mucus that drips from your nasal passage into the back of your throat
• Dark circles under your eyes (called “allergic shiners”) caused by increased blood flow near your sinuses
• Fatigue
• Shortness of breath
• Stuffed up ears or hearing loss
• Aggravation of asthma
• Snoring
• Itchy throat, mouth or nose

Allergies — or something else? If you have a fever or have a thick yellow or green mucus discharge, then you may have a sinus infection and you should see your doctor.