Miles Weinberger, MD
Professor of Pediatrics
Allergy, Immunology, and Pulmonary 

An asthma diary can provide your physician with invaluable firsthand information regarding your asthma. As you well know, symptoms of asthma fluctuate and may not be present at all when you see your doctor. Your physician, however, must make decisions regarding the medical indications for adding, continuing, or withdrawing medication. The diary provides information that is more accurate than trying to remember what happened over weeks or months when you are seen for a scheduled medical appointment. This, in turn, results in better medical decisions.

The question regarding asthmatic symptoms "last night" should be completed upon awakening in the morning. The second question line asks for a "morning peak flow" measurement. Most patients are not asked to keep track of peak flow measurements. This procedure is discussed separately. The subsequent questions are completed at bedtime and ask about symptoms during the day. Keeping a pencil beside the bed and completing the diary at bedtime and on arising is probably the easiest way of not forgetting. Always bring the diary with you to appointments with your physician.

Two sample diaries that can be copied, printed, and used are illustrated in Figure 2 and Figure 3 (simplified for children and adults with lesser language skills).

Interpreting the allergy evaluation and understanding the role of environmental factors in asthma

Asthma is not caused primarily by allergy. Neither are nasal symptoms necessarily caused by allergy. There first has to be a predisposition or sensitivity of the nose or lungs. However, inhaled allergens often aggravate the bronchospasm and airway inflammation of asthma and the stuffiness, congestion, and drainage from the nose. Allergens include such substances as pollens, mold spores, animal danders, substances in dusts (dust mite fomite), and sometimes specific types of exposures in the workplace.

Allergens cause symptoms when they react with specific types of antibodies (of the IgE immunoglobulin class) that reside in the mucous membranes of the respiratory tract. This reaction results in the release of substances that cause constriction of muscle around the airway (bronchospasm) and inflammation of the mucous membrane of the airways which causes swelling of the tissues lining the airways and secretion of mucous into the airway (see figure 1). In the nose, this can result in sneezing, itchy nose, and runny nose. In the lungs, this results in tightness of the chest, coughing, wheezing, and labored breathing. It is important in managing asthma to identify the extent to which allergic factors contribute to the disease. And if allergic factors do contribute substantially to the disease, it is important to identify the specific allergic substances.

The evaluation for allergy involves a careful history of the environment and its relationship to your symptoms. Allergy testing identifies the type of antibody that causes allergic reactions in the airways. Both components of this evaluation are important in making clinical judgments regarding the importance of allergy in causing symptoms and in identifying what environmental factors, if any, may be causing problems with the nose or lungs.

There are two types of tests used to identify antibodies that cause allergic respiratory reaction. Allergy skin testing is most common. This involves exposing the tissues immediately below the outer surface of the skin to an extract of allergen (pollen, animal dander, dust mite, etc.) either by a superficial puncture, prick, or scratch or by injection of material just under the skin with a small needle. The size of local swelling and redness is then measured in 15 minutes. There are also blood tests for measuring the same type of antibody in a laboratory test. The blood tests are usually less sensitive, are no more accurate, and are usually more expensive than skin testing. They may be useful, however, when there is difficulty in interpreting skin tests.

The presence of positive skin tests or laboratory tests for the allergic antibodies do not, by themselves, indicate that usual natural exposure to those allergens will cause an allergic reaction. This depends on the degree of sensitivity of the airways, the degree of exposure, and perhaps other variables that we do not fully understand. The presence of the antibodies only indicates the potential for exposure to cause symptoms. The final decision as to whether exposure actually does cause symptoms is a clinical judgment based on evidence accumulated from the history and the allergy testing combined.

Not all environmental factors that aggravate respiratory problems are allergic. Cigarette smoking, whether by the patient or those around the patient, can cause respiratory symptoms through a direct irritant effect. Similar irritation may occur from open fires such as those in fireplaces and wood stoves. Strong odors and chemical irritants may also trigger the sensitive airways of the asthmatic patient. Skin testing will not be useful in identifying the potential for these irritant substances to cause symptoms.