The most effective way to beat allergy symptoms this fall is to prevent them. You may be especially susceptible to allergy symptoms such as frequent sneezing, itching and watery eyes inside your home. Long-term exposure to stale, humid air and various airborne allergens can trigger late onset allergy symptoms. Doctors are reporting more people being diagnosed with allergies later in life, as well as children and adolescents. Along with the increase in allergy sufferers, fortunately, scientists and HVAC contractors alike are getting better at recommending ways of allergy prevention inside the home: