Brief overview
- What is bronchiolitis? Collective term for inflammatory diseases of the lower, finely branched airways (bronchioles), which can be acute or chronic.
- Symptoms: in acute, infectious bronchiolitis (like RSV bronchiolitis) rhinitis, fever, sore throat, cough, breath sounds, possibly shortness of breath. In bronchiolitis obliterans, mainly dry cough and slowly increasing dyspnea.
- Diagnosis: history, physical examination, imaging (X-ray, high-resolution CT), pulmonary function test, measurement of oxygen saturation, lung endoscopy and lung biopsy if necessary.
What is bronchiolitis?
“Bronchiolitis” is a collective term for various diseases of the lower respiratory tract that arise in different ways and can also be variable. It is either an inflammation or an obstruction (obliteration) of the finest airways (bronchioles) due to inflammation, as well as the adjacent tissue.
The lower airways
Their diameter is less than one millimeter. Their thin walls contain fibers of smooth muscle that regulate the diameter of the airways through relaxation and tension. The walls are covered on the inside with a mucous membrane (as in the entire respiratory tract). Bronchioles conduct the inhaled air to the actual places of gas exchange – alveoli (alveoli).
Causes and forms of bronchiolitis
- acute bronchiolitis: usually caused by viruses or other infectious agents (infectious bronchiolitis), in other cases, for example, by inhalation of gases/toxins, liquids or solids, or as a result of Wegener’s granulomatosis (granulomatosis with polyangiitis).
If the cause of acute or chronic bronchiolitis remains unknown, physicians refer to it as idiopathic bronchiolitis.
Other possible causes of bronchiolitis obliterans are diseases of the lung parenchyma (internstitial lung diseases), rheumatic diseases, toxic gases or drugs. Rejection reactions after heart-lung, lung or bone marrow transplantation can also cause the clinical picture. This is called bronchiolitis obliterans syndrome (BOS).
Other disease: bronchiolitis obliterans with organizing pneumonia
Children very frequently affected
Acute infectious bronchiolitis is widespread and is usually caused by viruses, mainly the respiratory syncytial virus (RS virus). It primarily affects children between the ages of two and six months. In infancy, acute bronchiolitis is the most common viral infection of the lower respiratory tract. In the first year of life, bronchiolitis is the most common reason for hospitalization.
Can bronchiolitis be cured?
RSV bronchiolitis
RSV bronchiolitis has a slightly higher mortality rate in premature infants (1.2 percent), children with the chronic lung disease bronchopulmonary dysplasia (4.1 percent), and children with congenital heart defects (5.2 percent).
To learn which factors – in addition to prematurity, bronchopulmonary dysplasia and congenital heart defect – favor a severe course in RSV infection, click here.
Bronchiolitis obliterans
Bronchiolitis: What are the symptoms?
Acute infectious bronchiolitis generally manifests with nonspecific symptoms of respiratory infection such as rhinitis, low-grade fever, sore throat, and cough. In most cases, it is RSV bronchiolitis:
Usually, the cough then becomes more pronounced and increasingly productive (i.e., associated with sputum), and breathing difficulties and even shortness of breath occur: The respiratory rate increases, i.e., the patient breathes faster. When breathing, the nostrils are often set up and the auxiliary respiratory muscles are used for support. The latter can be recognized by retractions of the skin in the jugular fossa or between the ribs during breathing.
In severe cases, the poor oxygen supply is manifested by a bluish discoloration of the skin/mucous membranes (cyanosis).
Other symptoms of RSV bronchiolitis include impaired general condition and problems with food intake (reflux, vomiting, refusal to drink in infants). The latter can quickly lead to dehydration in babies.
In infants younger than three months, respiratory distress is often the only symptom of RSV bronchiolitis.
Bronchiolitis: Diagnosis
In order to diagnose bronchiolitis, the physician must rule out other lung diseases with similar symptoms. Several examinations are necessary for this purpose.
Medical history and physical examination
- How long have the symptoms been present? Did they develop suddenly or rather slowly?
- What exactly are the symptoms?
- Is breathing difficult or is there shortness of breath?
- Are there any known pre-existing conditions such as connective tissue disease (collagenosis)?
- Have you / has the child had an organ or bone marrow transplant in the past?
- Are you / your child taking any medications? If yes, which ones?
- Do smokers live in your household?
This is followed by a physical examination. The physician listens to the patient’s lungs with a stethoscope and listens for breathing sounds: crackling or rustling breathing sounds are common signs of bronchiolitis. If the lungs are overinflated due to disease, the breath sounds are attenuated.
Not every patient with bronchiolitis has noticeable breath sounds.
Imaging diagnostics
In some patients, an X-ray examination of the chest (X-ray thorax) is necessary. This is especially the case in a severe and atypical course of the disease.
Pulmonary function test and oxygen saturation
Pulse oximetry measures how much oxygen is transported in the blood. If the lung tissue is damaged, oxygen exchange can no longer take place at the usual rate. As a result, the oxygen saturation of the blood decreases. If the saturation is normal, no further examination is required. If the pulse oximetry shows a value that is too low and at the same time there are breathing difficulties up to shortness of breath, this supports the diagnosis of bronchiolitis.
Pulmonary endoscopy & biopsy
During lung endoscopy (bronchoscopy), the physician inserts a flexible, tube-shaped instrument (endoscope) through the patient’s mouth or nose into the trachea. The thin tube carries a small camera and a light source at its front end. The doctor can use it to view the airways from the inside and thus detect any changes in the mucous membranes.
Bronchiolitis: Treatment
Bronchiolitis therapy depends on the cause and severity of the disease. Because generally applicable therapy recommendations are lacking in many cases, treatment is usually adapted individually to each patient.
If bronchiolitis is associated with another disease (such as asthma, rheumatoid arthritis, ulcerative colitis, etc.), this must also be treated appropriately.
Treatment of RSV bronchiolitis
It is important to drink enough fluids. This makes the mucus in the airways more fluid and thus easier to cough up.
Patients may also be given medication as needed. An antipyretic (e.g., paracetamol, ibuprofen) helps against high fever. A decongestant nasal spray can improve breathing in severely congested airways.
In the case of constricted bronchioles, patients receive special medication via an inhaler to widen the airways (bronchodilators).
Home remedies
For a mild course of RSV bronchiolitis, home remedies can aid recovery:
Inhalation is a proven home remedy for coughs and colds: the patient puts a towel over his head, holds his uncovered face over a pot or bowl of hot water, and deeply inhales the rising vapors. This soothes the affected mucous membranes, dilates the airways and helps to cough up the secretions.
Another home remedy for bronchiolitis is nasal irrigation (nasal douche). It also helps with rhinitis and mucous airways. In this procedure, the nasal cavity is thoroughly rinsed with saline solution. This removes germs from the upper airways and loosens the secretion.
Cool, moist calf compresses help against fever. They dissipate body heat to the environment, which lowers the increased body temperature. You can find out how to make and apply the compresses here.
Treatment in hospital
If the course of the disease is severe, with respiratory distress and low oxygen saturation in the blood, the affected person must be hospitalized. Also, if an infant is affected who refuses to drink as a result of bronchiolitis and is at risk of dehydration, hospitalization cannot be avoided.
Treatment of other forms of bronchiolitis
Antiviral agents (antivirals) are available for the treatment of some forms of viral bronchiolitis. For example, if an infection with herpes simplex viruses (HSV) is present, aciclovir can help.
Bronchiolitis: Prevention
Since there are different forms of bronchiolitis, it is not possible to give generally valid recommendations for disease prevention. However, in general, the following tips can help keep the lungs healthy and reduce the risk of lung disease:
- Sufficient fluid intake: Drink at least 1.5 liters a day (water, mineral water, tea, etc.) – this liquefies the secretions in the airways.
- Avoid nicotine: Stop smoking or do not start smoking in the first place. Also avoid passive smoking (i.e. staying indoors in smoke-filled rooms).
- Regular exercise: This promotes general health and strengthens the immune system.
- Use medications as directed: Always follow your doctor’s or pharmacist’s instructions exactly when using medications (even over-the-counter).
Breastfeeding is also beneficial for infants. Infants who are breastfed are less likely to suffer from respiratory illness than bottle-fed infants.
RSV bronchiolitis: prevention
To protect against common RSV bronchiolitis, experts recommend hygiene measures and RSV vaccination for children at increased risk.
Hygiene measures
- Regular and proper hand washing
- Sneezing and coughing into the crook of the elbow or into a handkerchief (not into the hands)
- Regularly and thoroughly clean your child’s toys
- Refrain from visiting community facilities if you or your child is showing symptoms
- Refrain from smoking (especially around children)
