Asthma, a common chronic childhood disease, affects 17 million people in the United States.  Unfortunately, the incidence of asthma is dramatically on the rise, particularly in highly developed parts of the world.  From the Greek word for panting or breathlessness, asthma is characterized as inflammation of the airway passages.  When inflammation occurs, the airway passage lining swells and produces mucus.  Bands of muscle begin to contract, further constricting the airway, already narrowed by increased mucus and fluid (congestion).  At this point, patients experience chest tightness, coughing, wheezing, and difficulty breathing.  Asthma is not just one disease; there are many subtypes of asthma classified by different triggers and disease processes.

Asthma is frequently caused by allergies (allergic asthma) and usually emerges during childhood, affecting more boys than girls.  Of those affected, about 90 percent of children under the age of sixteen have asthma of an allergic type.  Major factors in diagnosing allergic asthma include having a family history of allergies and seasonal allergy symptoms.  Tree, grass, and weed pollens, dust mites, animal dander, and even foods are known as common triggers of allergic asthma.  When these allergens interact with our IgE immunoglobulin, mast cells, eosinophils, and basophils trigger a release of chemical mediators.  These mediators, including histamine, prostaglandins, and leukotrienes produce inflammation of the airway passage lining.

Occupational asthma is defined as asthma that is caused by breathing in chemical fumes, gases, dust, or other substances on the job.  Occupational asthma can result from exposure to a substance that one is sensitive to, triggering an allergic or immunological response.  Asthma can also be triggered by exercise, called exercise-induced bronchoconstriction.

Aspirin or NSAID-induced asthma is due pharmacological reactions blocking the cox-1 enzyme and an overproduction of pro-inflammatory chemical mediators.  This is not, in fact, a true allergic reaction to aspirin or NSAIDS.  It is frequently associated with chronic rhinosinusitis and nasal polyps.

The main symptom of cough-variant asthma is a dry, non-productive cough.  This type of asthma is common in youngsters with childhood asthma and can lead to the development of “classic” asthma, with symptoms that include shortness of breath and wheezing.

Eosinophilic asthma is a relatively rare but severe form of asthma.  It is commonly seen in people who develop asthma as an adult, usually age 35 to 50, although it may occur in children.  Patients with eosinophilic asthma do not typically have underlying allergies (e.g., pollens, dust mites, pet dander) that trigger asthma symptoms. Asthma is diagnosed based on symptoms, a physical examination, lung function test, allergy skin test, and eosinophils from blood or sputum.  The accurate diagnosis of different subtypes of asthma is crucial to avoid particular triggers and target specific disease processes with precise, effective treatment.