Types of Allergies
Allergies are often worse for patients during the pollinating season. This is termed seasonal allergic rhinitis or hay fever. Hay fever is caused by pollens. The most significant pollen in the US is ragweed. It begins pollinating in late August and continues until the first frost. Late spring-time pollens come from the grasses, such as Timothy, Orchard, Red Top, Sweet Vernal, Bermuda, Johnson, Brome and Bluegrass. Early spring-time hay fever is most often caused by pollens of trees such as Elm, Maple, Birch, Poplar, Ash, Willow, Oak, Cottonwood and Alder. Colorful or fragrant flowering plants rarely cause allergies because their pollens are too heavy to be airborne.
Certain allergens are always present. These include house dust, household pet danders, foods, wool, various chemicals used around the house, and more. These are termed perennial or year-round allergens. Symptoms from these are frequently worse in the winter when the house is closed up. Mold spores cause at least as many allergy problems as pollen. Molds are present all year long and grow outdoors and indoors. Dead leaves, farm areas and lawns are common sources for outdoor molds. Indoor plants, old books, bathrooms and damp areas are common sources of indoor mold growth. Molds are also common in foods, such as cheese and fermented beverages.
Patients who react quickly and violently to oral medications or specific foods have food allergies. These are termed fixed allergies and are often seen with oral penicillin or peanuts. Once someone has a fixed food or drug allergy, they will always be sensitive to it. The main treatment is simple avoidance, although most patients also carry epinephrine in case of accidental ingestion. These patients can also have adverse reactions to foods that are non-allergic, including lactose intolerance, intolerance to MSG, or even food poisoning There is, however, a growing body of evidence that many foods can affect patients in more of a delayed fashion. These are called cyclic food allergies. The symptoms are more chronic in nature and usually do not manifest themselves for hours, or even a couple of days after the food is eaten. Another phenomenon called “masking” happens when the offending food can actually offer temporary relief of the symptoms. This can often lead to the patient actually craving the food to which they are allergic. There are a number of ways to test for this.