Asthma

What it is

Asthma is a heterogeneous disease, usually characterized by chronic airway inflammation. Variability runs through it on two sides: clinically, variable respiratory symptoms; physiologically, variable expiratory airflow limitation. Asthma severity and asthma control are not the same thing, and each has its own criteria: 1. severity is set in the patient who is not yet on controller medication, and it decides the step at which treatment starts; 2. control is measured in the patient already on treatment, and it decides whether to step up or step down.

Causes and risk

Pediatric asthma is the most commonly encountered chronic illness, occurring in nearly one out of seven individuals. Symptoms are variable in three ways: diurnal, that is day and night; seasonal, over spring, summer, fall and winter, following tree pollen, grass pollen, weed pollen and mold; and by trigger, the triggers being infections, smoke, exercise and irritant smells.

How it presents

The symptoms are cough, chest tightness, shortness of breath and wheezing. At least one of the following three criteria qualifies a patient as having uncontrolled asthma:

1. Frequent exacerbations: 2 or more a year requiring oral corticosteroids.
2. Serious exacerbations: 1 or more a year requiring hospitalization.
3. Poor symptom control: frequent symptoms or reliever use, activity limited by asthma, or night waking due to asthma.

Control is also measured with a named instrument, the Asthma Control Test, and its five items each score 1 to 5, worst to best:

1. In the past 4 weeks, how much of the time did your asthma keep you from getting as much done at work, at school or at home? All of the time 1, most of the time 2, some of the time 3, a little of the time 4, none of the time 5.
2. During the past 4 weeks, how often have you had shortness of breath? More than once a day 1, once a day 2, 3 to 6 times a week 3, once or twice a week 4, not at all 5.
3. During the past 4 weeks, how often did your asthma symptoms - wheezing, coughing, shortness of breath, chest tightness or pain - wake you up at night, or earlier than usual in the morning? 4 or more nights a week 1, 2 to 3 nights a week 2, once a week 3, once or twice 4, not at all 5.
4. During the past 4 weeks, how often have you used your rescue inhaler or nebulizer medication such as salbutamol? 3 or more times per day 1, 1 or 2 times per day 2, 2 or 3 times per week 3, once a week or less 4, not at all 5.
5. How would you rate your asthma control during the past 4 weeks? Not controlled at all 1, poorly controlled 2, somewhat controlled 3, well controlled 4, completely controlled 5.

The total is read in three bands: 20 or above is controlled asthma, 16 to 19 is partially controlled, and under 16 is uncontrolled.