Bronchiolitis in children: understand how the RSV virus causes infection and the main warning signs

The circulation of respiratory viruses intensifies at certain times of the year, putting parents and those responsible for newborns and young children on alert. Entre The most common and worrying diseases is bronchiolitis, an acute infection of the lower airways that can evolve quickly, requiring immediate medical attention. In most cases, the main causative agent is the respiratory syncytial virus (RSV), which is highly contagious and responsible for a significant portion of pediatric hospitalizations due to respiratory problems.

The infection directly affects the bronchioles, which are the thinnest branches of the bronchi within the lungs. Quando Inflamed, these small tubes fill with mucus and swell, making it difficult for air to pass through. Para babies, whose airways are already naturally narrow, this obstruction represents a high risk of respiratory failure, making early identification of symptoms a crucial factor for a positive outcome.

According to experts, RSV is responsible for about 75% of all bronchiolitis diagnoses, especially in children under two years of age. Nessa age group, the vulnerability of the still developing immune system and the small caliber of the airways contribute to a greater severity of the disease, increasing hospitalization rates and, in more serious cases, mortality.

The mechanism of action of the virus in the body

Bronchiolitis is a respiratory syndrome that sets in after the virus infects and multiplies in the cells of the upper respiratory system, such as the nose and throat. From there, it migrates to the lower airways, triggering an intense inflammatory response in the bronchioles. The infectologist Pediatric pulmonologist Karina Pierantozzi Vergani adds, explaining that the accumulation of mucus prevents adequate air from reaching the pulmonary alveoli, which are the structures responsible for gas exchange. With less oxygen reaching the bloodstream, the child’s body has to work much harder to breathe, causing extreme fatigue and visible breathing difficulties.

Early signs that deserve attention

The illness often begins with symptoms similar to a common cold, which can confuse parents in the early days. The most common initial signs include low-grade fever, clear runny nose and dry, persistent cough.

It is common for the child to also present irritability and a slight loss of appetite, a reflection of the general malaise caused by the viral infection in its initial stage.

These symptoms can last two to three days before the infection progresses to the lower airways, at which point the clinical picture tends to worsen.

Close monitoring of this phase is essential, as the transition to more severe symptoms can occur suddenly, especially in babies under six months.

Warning symptoms to seek medical help

After the initial phase, the inflammation of the bronchioles intensifies, and the symptoms become more characteristic and worrying. The cough becomes more productive and persistent, often occurring in crises that leave the child exhausted and can even cause vomiting. The most classic sign is wheezing, a high-pitched, hissing sound that can be heard when the child exhales, indicating that air is passing through narrowed airways. Respiratory fatigue is another important warning sign. Parents may notice that their baby’s breathing is more rapid and shallow than normal. The elevated respiratory rate is the body’s attempt to compensate for low oxygenation.

In more severe cases, clear signs of respiratory effort appear. One of them is the retraction of the ribs, when the skin between them sinks with each inhalation. Outros indicators include the flapping of the wings of the nose, a movement of opening the nostrils to try to capture more air, and the sinking of the wishbone, the bone located at the base of the neck. Difficulty feeding is also a sign of seriousness, as the baby becomes so tired that he cannot coordinate sucking with breathing. Refusal of fluids can quickly lead to dehydration, a serious complication that worsens the general condition and often requires hospital intervention for intravenous hydration.

How the treatment is carried out

As it is a viral infection, there is no specific medication that cures bronchiolitis. Treatment is focused on relieving symptoms and supporting the child’s body so it can fight the virus.

The main measures include frequent nasal clearance with saline solution, which helps the child breathe and eat better. Manter hydration is vital, offering liquids in small amounts and more frequently.

To control fever and malaise, your doctor may recommend the use of antipyretics. It is important to note that antibiotics are not effective against RSV and are only prescribed if there is an associated secondary bacterial infection, such as otitis or pneumonia.

When hospitalization is necessary

The decision to hospitalize a child with bronchiolitis depends on the severity of the symptoms and their ability to maintain oxygenation and hydration. If the child has intense respiratory effort, cyanosis (bluish color on the lips or nails) or suboptimal oxygen saturation, hospitalization is indicated to provide oxygen support.

Babies that are very small, premature or have comorbidities, such as heart or lung disease, are at greater risk of developing severe forms of the disease and generally require closer hospital monitoring.

Effective prevention measures

Bronchiolitis prevention involves simple hygiene measures, which are highly effective in reducing the transmission of RSV and other respiratory viruses. Frequent hand washing with soap and water or the use of alcohol gel is the main recommendation.

Avoiding contact between babies and people who have cold or flu symptoms is essential. Também closed environments with large crowds of people should be avoided, especially during the months when the virus is most circulating.

Immunization available for risk groups

Although there is not yet a vaccine widely available for the general population against RSV, there is a form of passive immunization with the monoclonal antibody called Palivizumabe. Ele is indicated for high-risk groups, such as extremely premature babies and children with severe chronic heart or lung disease. Monthly application during the period of greatest circulation of the virus helps prevent serious cases and hospitalizations in this vulnerable population.