Asthma is a common, long-term respiratory condition characterized by chronic inflammation in the airways, causing them to narrow and become overly responsive to triggers. This leads to recurring symptoms like wheezing, coughing, chest tightness, and shortness of breath. Because the frequency and intensity of symptoms vary significantly, medical professionals classify asthma based on its severity before treatment begins. Understanding the specific classification, such as moderate persistent asthma, is the first step toward effective long-term management.
The Spectrum of Asthma Severity
Classifying asthma severity guides the initial choice of medication through the stepwise approach. This systematic framework ensures that treatment is matched to the patient’s underlying disease burden. The classification helps determine the starting point for daily controller medication, which is adjusted over time to achieve optimal asthma control.
Asthma severity is generally divided into four categories for patients over five years old: Intermittent, Mild Persistent, Moderate Persistent, and Severe Persistent. The basic distinction is between intermittent asthma, where symptoms occur only occasionally, and persistent asthma, which indicates a more regular, ongoing presence of symptoms.
Moderate persistent asthma sits between the mild and severe ends of the spectrum. Symptoms are frequent enough to regularly interfere with life but are not yet constant or highly debilitating. This framework allows clinicians to gauge the disease intensity and select a corresponding treatment step. The classification is based on symptom frequency, the need for rescue medication, nighttime awakenings, and lung function test results before a patient starts long-term control medication.
Specific Diagnostic Criteria
A diagnosis of moderate persistent asthma is assigned when symptoms and lung function fall within specific clinical parameters. Daytime symptoms, such as coughing, wheezing, and shortness of breath, typically occur every day. This daily frequency often necessitates the daily use of a short-acting beta-agonist (SABA), or rescue inhaler, to quickly relieve acute symptoms.
Nighttime awakenings are another measure of severity. In moderate persistent asthma, these occur more than once a week, but not every night. This usually translates to five or more episodes of being woken by asthma symptoms per month. The frequent symptoms and need for rescue medication result in a moderate limitation on normal physical activity.
Lung function tests, measured by spirometry, provide objective data for classification. A key measurement is the Forced Expiratory Volume in one second (FEV1), which measures the amount of air a person can forcefully exhale in that time. For moderate persistent asthma, the FEV1 is typically between 60% and 80% of the predicted value for a person of the patient’s age, sex, and height. The Peak Expiratory Flow (PEF), the maximum speed of expiration, also shows high variability, often greater than 30% from morning to afternoon. These measurable criteria ensure a uniform approach to classifying disease severity.
Standard Management and Treatment Goals
The standard therapeutic strategy for managing moderate persistent asthma is classified as Step 3 in the stepwise approach, focusing on daily controller medications. The preferred treatment involves a combination of two types of inhaled medicine delivered via a single device: a low-dose inhaled corticosteroid (ICS) and a long-acting beta-agonist (LABA).
The ICS targets chronic inflammation in the airways, while the LABA provides sustained bronchodilation, helping to keep the airways open. Alternatively, treatment may involve a medium-dose ICS alone, or a low-dose ICS combined with a leukotriene receptor antagonist (LTRA). These controller medications must be taken daily, regardless of symptoms, to prevent future exacerbations.
The goal of this management strategy is to achieve and maintain asthma control. This means minimizing chronic symptoms, having few or no nighttime awakenings, and requiring only infrequent use of the SABA rescue inhaler. Achieving control also means maintaining near-normal lung function and allowing the patient to participate in all normal activities without limitation. Regular follow-up with a healthcare provider is important for reassessing symptoms and lung function to determine if the current treatment step is successful or if an adjustment is needed to maintain optimal control.