Dr. Derek Kendall Johnson gives thorough advice on how to keep allergens under control through cleaning and lifestyle choices.

Q. What first drew you to specialize in the area of allergies and immunology?

Dr. Johnson: Medicine is one of the few remaining disciplines that is still taught mostly as an apprenticeship, where the student learns from a series of mentors who are charged with the task of passing along not only the science of medicine but the art of healing. Early in my training, I was fortunate to spend time working under an amazing physician who happened to be an immunologist. Although I studied many other areas of medicine in the years that followed, I was always intrigued by the complexity of the immune system, and how this often overlooked system was able to recognize "self" from "non-self." Without this ability, humans wouldn't be able to fend off infection and would be incapable of survival on Earth. I also found great satisfaction in the way that I was able to help my patients by manipulating this very same system to alleviate allergic disease–which is really just an over-active immune system.

Q. How has spending so much time with children increased your understanding of the difficulties that kids with allergies face?

Dr. Johnson: Children have unique needs when it comes to diagnosis and treatment of allergies and related illnesses. Because the immune system is not fully developed in young children, they tend to catch the common cold more frequently. This leads to confusion in diagnosis, and may make treatment more difficult. Many parents attribute symptoms such as nasal congestion and red eyes to allergy, when in fact, irritants such as dirt, chemicals and cigarette smoke are the culprits. Children also need more sleep than adults do in order to function well during the day. Nasal obstruction and coughing triggered by allergy may interfere greatly with sleep. This leads to problems with behavior and learning in school, and even with physical performance in sports and other activities. Seeking the advice of a pediatric allergist is important in sorting out a potentially confusing diagnosis.

Q. What times during the year do allergy symptoms tend to spike (dust allergies as well as seasonal)? What causes these fluctuations?

Dr. Johnson: Hay is really Timothy grass, and they don't call it "Hay Fever" for nothing! Pollen allergies are seasonal, with tree pollen being a problem in the early spring, grass pollen in the late spring and early summer, and weed pollen in the fall. These plants depend on the wind to spread pollen, and they produce large quantities at certain times of the year. When pollen levels spike, allergy sufferers can become miserable.

Indoor allergens include pet dander, cockroach, dust mites and mold. Exposure to these allergens can occur at any time during the year, but some can be more pronounced in certain seasons–mold in the humid, rainy season, for example. One common misperception is that "house dust" is responsible for most indoor allergies. Although house dust may contain some on the above allergens, the real culprit is dust mite allergen. This is a digestive protein produced by tiny organisms found mostly in bedding, carpets and upholstery, and can be very difficult to get rid of.

Q. Can allergies develop out of the blue, as with a new pregnancy or even as a child simply grows older? Are there ways to anticipate these developments?

Dr. Johnson: Allergies can develop at any time during a person's life. However, most allergy sufferers will develop symptoms before age 20. Many people don't know that babies aren't born with any allergies at all. After time, the immune system begins to develop a reaction to certain proteins (the allergens), and future exposures to these allergens leads to symptoms. The exact reasons that one person may develop allergies and another may not aren't entirely clear. We do know, however, that children with parents that have allergies are much more likely to develop allergies themselves. It may be difficult to anticipate the development of allergies, but understanding the symptoms of allergies and the things that cause them can help immensely in allowing parents to seek appropriate diagnosis and treatment. Many pregnant women report an increase in allergy symptoms, while others actually report an improvement.

Q. Do you have any simple, routine lifestyle or cleaning tips to reduce allergens around the home?

Dr. Johnson: Many people confuse allergy prevention and cleaning. A "dirty" or dusty home may harbor many allergens, but a clean one may as well. The use of HEPA filters in your home heating system and vacuums is a good first step. Dust mite allergens are reduced by washing bedding in hot water and using a high heat setting on the dryer. Also, allergy mattress and pillow encasements can reduce ongoing exposure to mite allergen. In northern climates, people frequently use humidifiers in the winter, both the table–top style as well and whole–home versions. These products promote mold, mildew and dust mite growth, so it is really best to avoid using them altogether. If humidifiers are to be used, clean them frequently according to manufacturer's instructions.

Q. Would you recommend any particular cleaning products that work especially well to counteract allergens?

Dr. Johnson: Many cleaning products work well. I recommend avoiding anything that has much of an odor, as strong smells tend to aggravate allergy–like symptoms and asthma. Review cleaning products and other mechanical devices such as in–room air cleaners before spending your money. Many of these products are very expensive and provide very little benefit.