Inflammation of the bronchioles, often associated with bronchopneumonia.
Bronchiolitis is an acute inflammatory injury of the bronchioles that is usually caused by a viral infection. Although it may occur in persons of any age, severe symptoms are usually only evident in young infants; the larger airways of older children and adults better accommodate mucosal edema. Bronchiolitis usually affects children younger than 2 years, with a peak in infants aged 3-6 months. Acute bronchiolitis is the most common cause of lower respiratory tract infection in the first year of life. It is generally a self-limiting condition and is most commonly associated with respiratory syncytial virus.
Wilhelm Lange first described obliterative bronchiolitis (OB) in 1901 by reporting 2 cases of interstitial bronchiolar disorder. In 1985, bronchiolitis obliterans-organizing pneumonia (BOOP) was described as a separate condition with different clinical, radiographic, and prognostic features than OB. BOOP is a histopathologic lesion, not a specific diagnosis. Its pathologic hallmark is proliferative bronchiolitis or bronchiolitis obliterans in association with organizing pneumonia.
According to the World Health Organization bulletin, an estimated 150 million new cases occur annually; 11-20 million (7-13%) of these cases are severe enough to require hospital admission. Worldwide, 95% of all cases occur in developing countries.
Most cases of bronchiolitis are not easily preventable because the viruses that cause the disorder are common in the environment. Careful attention to hand washing, especially around infants, can help prevent the spread of respiratory viruses.
Family members with an upper respiratory infection should be especially careful around infants. Wash your hands often, especially before handling the child.
At this date, there is no RSV (Respiratory Syncytial Virus) vaccine available. However, there is an effective product, called palivizumab (Synagis), for infants who are at high risk of developing severe disease from RSV. Ask your child's doctor whether this medication is right for your child.
Some children have infections with few or minor symptoms.
Bronchiolitis begins as a mild upper respiratory infection that, over a period of 2 to 3 days, can develop into increasing respiratory distress with wheezing and a "tight" wheezy cough.
The infant's breathing rate may increase a lot (tachypnea), and the infant may become irritable or anxious-looking. If the disease is severe enough, the infant may turn bluish (cyanotic), which is an emergency.
As the effort of breathing increases, parents may see the child's nostrils flaring with each breath and the muscles between the ribs retracting (intercostal retractions) as the child tries to breathe in air. This can be exhausting for the child, and very young infants may become so tired that they have difficulty maintaining breathing.
Bluish skin due to lack of oxygen (cyanosis).
Causes and Risk factors:
- Cough, wheezing, shortness of breath, or difficulty breathing.
- Fever Intercostal retractions.
- Nasal flaring in infants.
- Rapid breathing (tachypnea).
Bronchiolitis usually affects children under the age of 2, with a peak age of 3 to 6 months. It is a common, sometimes severe illness. Respiratory Syncytial Virus
(RSV) is one common cause. Other viruses that can cause bronchiolitis include:
The virus is transmitted from person to person by direct contact with nasal secretions or by airborne droplets. Although RSV generally causes only mild symptoms in an adult, it can cause a severe illness in an infant.
Bronchiolitis is a contagious condition. Virus transmission occurs through direct contact with nasal secretions from person to person. It can also occur due to airborne droplets. Bronchioles are the smallest airway passages of the lung. Viruses reach to the respiratory system and goes to the bronchioles. Bronchioles get swollen due to these viruses.
Mucus collection occurs in these airways, making air flowing difficult into lung. Infants' bronchioles are smaller than older children. So, infants face more problems while breathing than older ones.
Bronchiolitis is seasonal and appears more often in the fall and winter months. It is a very common reason for infants to be hospitalized during winter and early spring. It is estimated that by the first year, more than half of all infants have been exposed to RSV.
Risk factors include:
Being exposed to cigarette smoke.
- Being younger than 6 months old.
- Living in crowded conditions.
- Never being breastfed.
- Prematurity (born before 37 weeks gestation).
The diagnosis of bronchiolitis is based on clinical presentation, the patient's age, seasonal occurrence, and findings from the physical examination. Tests are typically used to exclude other diagnoses, such as bacterial pneumonia, sepsis, or congestive heart failure, or to confirm a viral etiology and determine required infection control for patients admitted to the hospital.
The most common tests are rapid viral antigen testing of nasopharyngeal secretions for RSV, blood gas analysis, WBC count with differential, C-reactive protein
(CRP) level, and chest radiography. Other common tests are pulse oximetry, blood culture, urine analysis and culture, and cerebrospinal fluid analysis and culture.
The treatment of bronchiolitis is based on the physical examination of the child and the symptoms of the disease. Mild bronchiolitis can be treated at home. Paracetamol syrup is generally prescribed to control the fever and the discomfort of the child. Besides, the child is made to drink sufficient amount of fluid in order to avoid dehydration.
Though antibiotics are not needed but the doctor may prescribe bronchodilator drug that will help the child to breathe properly. In case of severe bronchiolitis, the child should be taken to the hospital for treatment. The babies suffering from severe bronchiolitis will be provided with humidified oxygen. This is given into the nose of the babies through a tube. In more severe cases the babies may be given artificial ventilation.
In case of severe bronchiolitis the babies are generally taken to hospital for treatment. Often the babies are provided with nasopharynx suction. This is generally done to keep the air passage of the lungs clear. Doctors often give medicines like ipratropium or salbutamol/albuterol to see if it works. These medicines are prescribed for babies who have a family history of asthma. Another drug that is given in this case is Racemic epinephrine.
Doctors often prescribe Ribavirin for treating bronchiolitis caused by RSV virus. This drug is used for treating bronchiolitis in children having pre-existing heart or lung problem. Doctors also prescribe antibiotics for treating severe bronchiolitis. However, hypertonic saline is given children suffering from bronchiolitis as it helps in increasing the hydration of the body.
Vaccines are not available for bronchiolitis. However, palivizumab medication can decrease the possibility of RSV infections in infants with a high risk.
Medicine and medications:
Medications have a limited role in the management of bronchiolitis. Several drugs are commonly used, but little or inconclusive evidence supports the routine use of any drug in the management of bronchiolitis.
Some of the medications include:
- Albuterol (Proventil, Ventolin).
- Prednisone (Orasone, Sterapred, Meticorten).
- Ribavirin (Virazole).
- Helium-oxygen (Heliox).
: The following drugs and medications are in some way related to, or used in the treatment. This service should be used as a supplement to, and NOT a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners.
DISCLAIMER: This information should not substitute for seeking responsible, professional medical care.