Viral-induced asthma is a respiratory condition where a viral infection, like the common cold, triggers asthma symptoms or an attack. It is particularly common in young children whose immune systems are still developing, but it affects adults as well. For many children younger than three, the condition is not permanent and can be outgrown. However, it requires medical attention to manage symptoms and prevent complications. Viral infections are linked to a high percentage of asthma flare-ups—up to 95% in children and 80% in adults.
The Viral Triggers and Mechanism
The primary triggers of viral-induced asthma are common respiratory viruses. The most common is the rhinovirus, which causes the common cold. Other triggers include respiratory syncytial virus (RSV), a major cause of respiratory illness in young children, and the influenza virus. These viruses infect the cells lining the airways.
Once an infection is established, the body’s immune system responds. In individuals with asthma or a predisposition to it, this immune response is heightened. The infection leads to inflammation in the airways, causing them to swell and become more sensitive, a state known as airway hyperresponsiveness. The smooth muscles that encircle the airways then tighten, a process called bronchoconstriction, while the irritated airways produce excess mucus, further obstructing airflow and making breathing difficult.
Recognizing the Symptoms
The initial signs of viral-induced asthma often start with cold symptoms, like a runny nose or sore throat. As the condition progresses, these develop into asthma symptoms. This can include a persistent cough that worsens at night or during physical activity. It is frequently accompanied by wheezing, a whistling sound that occurs when breathing, especially when exhaling.
To distinguish these symptoms from a simple viral illness, note their severity. While a standard cold causes a cough, the cough with viral-induced asthma is more prolonged and severe. The main difference is the presence of breathing difficulty. Shortness of breath and chest tightness or pain are signs of asthma, not a typical cold. In children, signs of labored breathing, like skin pulling in around the ribs and neck, may also be observed.
Diagnosis and Medical Evaluation
A diagnosis of viral-induced asthma is frequently based on a recurring pattern where asthma-like symptoms consistently appear following a viral respiratory infection. This connection is a strong indicator that viruses are triggering the respiratory distress. The diagnostic process begins with a review of the patient’s medical history and a discussion about the timing and frequency of the symptoms.
During a physical exam, a doctor will listen to the lungs with a stethoscope to detect wheezing. To determine if there is an underlying asthma condition, lung function tests may be performed when the patient is not sick. One such test is spirometry, which measures how much air a person can exhale and how quickly, assessing the general health of the lungs.
Treatment and Management Approaches
Managing viral-induced asthma involves both immediate relief from acute symptoms and long-term strategies to control the condition. For acute episodes, quick-relief “rescue” medications are used to rapidly open the airways. The most common of these are short-acting beta-agonists (SABAs), like albuterol, which relax the muscles around the airways. These bronchodilators provide fast relief from wheezing and shortness of breath during an attack.
Long-term management focuses on reducing airway inflammation to make them less reactive to viral triggers. Inhaled corticosteroids are the most common long-term control medications. Drugs like fluticasone and budesonide are taken daily to reduce swelling and sensitivity in the airways. A combination inhaler with a corticosteroid and a long-acting beta-agonist (LABA) may also be prescribed.
Preventative measures are also part of management. An annual flu shot can reduce the risk of influenza-triggered attacks, and frequent hand washing helps lower the chance of contracting respiratory viruses. Anyone diagnosed with this condition should have a personalized asthma action plan from their doctor. This plan outlines how to use medications and when to seek emergency care.