Bronchiolitis In Adults
What is Bronchiolitis?
Bronchiolitis is a viral infection affecting bronchioles which are small airways in the lungs resulting in the narrowing of these airways.
It occurs in children under two years of age. It has been reported that the incidence of bronchiolitis under one year of age is 11-15%. It mainly occurs in winters and early spring. Adults are rarely affected by Bronchiolitis.1
What is the difference between Bronchiolitis and Bronchitis?
Bronchiolitis and bronchitis may seem similar due to some common symptoms but understanding their difference is essential.
Viruses are the cause of bronchitis and bronchitis. Also, airways are obstructed in both of them. But in bronchiolitis, bronchioles are affected, and in bronchitis, bronchi are affected. (larger airways)
Bronchiolitis is common in younger children and infants, while bronchitis affects adults and older children.
Causes Of Bronchiolitis
The main culprit of bronchiolitis is a respiratory syncytial virus, influenza virus, and rhinovirus. Their highly contagious nature causes them to spread at a fast pace. They are transferred from person to person by touching the droplets from the mouth or nose and by respiratory droplets in the air. Bronchiolitis happens when someone sneezes or coughs without adequately covering their mouth.
Risk Factors
Some of the risk factors include:
1) Low birth weight
2) Poor socioeconomic status
3) Lung or heart anomaly
4) Living in a crowded environment where the virus is present, like daycare centers
5) Infants less than five years old
6) Immunodeficiency disorder
7) Chronic lung disease
8) Parental smoking
9) Not being breastfeed.1.
Signs and Symptoms
According to the American Lung Association, signs and symptoms of Bronchiolitis resemble closely to cold and flu. These include:
1) Runny nose
2) Cough
3) Stuffy or blocked nose
4) Fever ( less than 101° )
These may worsen after three days and start presenting with different symptoms which require more attention.
Wheezing ( a whistling sound from the chest during respiration) There can also be chest retraction, i.e., the skin of the ribs and chest sinks in while breathing.
1) Difficulty in breathing
2) Pauses in breathing
3) The child is irritable and fussy
4) Cried without tears
5) Fewer wet diapers than usual
6) Cough is worsened
7) Vomiting after eating
It's good to see a general physician if the child presents the following symptoms:
1) Extreme difficulty in breathing
2) having dry diaper even after 12 hours
3) Breathing at a faster rate ( more than 60 breaths a minute
4) Very irritable
5) Loss of appetite
6) Persistently having a fever above 100.4 F ( 38°C)
You must rush to emergency immediately or call 911 if the following symptoms are evident:
1) Child is sluggish
2)Troubled breathing
3) Bluish hue on the lips, tongue, and nails of the child.2
Types of Bronchiolitis
1) Viral Bronchiolitis
Viral Bronchiolitis is mainly caused by a respiratory syncytial virus(RSV). It's a common cause of hospital admissions of infants under one year. Initially, this may mimic an upper respiratory tract infection such as a common cold( runny nose, cough). It can quickly spread through coughing and sneezing.
Other causes of viral bronchiolitis include:
Adenovirus
It affects mucous membranes. About 5-10% of respiratory tract infections in children and 1-7% in adults are caused by them
2. Influenza virus
It causes inflammation of the nose, throat, and lungs. Both children and adults are affected by it, but it's dangerous in infants with a weak immune system.
Bronchiolitis Obliterans
Bronchiolitis obliterans is a chronic respiratory disease of the small airways of Bronchioles. It is also known as Popcorn lung and constrictive bronchiolitis.
Small airways can get injured after inhaling toxic substances like Chlorine, Ammonia, Formaldehyde, Acetaldehyde, and Nitrogen oxides or infection.
Scar tissue starts forming in the small airways if the cellular repair process goes into overdrive. This may result in blockage of bronchioles, thus preventing the passage of oxygen through the air sacs.
Bronchiolitis obliterans presents with symptoms of shortness of breath, wheezing, and cough. Narrowing of bronchioles can worsen over time resulting in respiratory failure.
Bronchiolitis in Adults
Adults rarely present with viral bronchiolitis, but they primarily develop what is called Bronchiolitis Obliterans or popcorn syndrome due to the appearance of the lungs as such.
Symptoms:
The symptoms of Bronchiolitis Obliterans develop in weeks and months and mainly includes:
1. Dry cough
2. Wheezing
3. Irritation of eyes, nose, mouth, and skin due to exposure to chemicals
4. Fatigue
5. Dyspnea or shortness of breath
This condition usually worsens when patients do any laborious work or during exercise.
Causes:
This rare condition usually occurs without any known cause. But few reasons are identified, which includes:
1. Fumes from cigarettes smoke
2. Fumes from chemicals like ammonia and chlorine.
3. Respiratory infections are also main causes of bronchiolitis obliterans.
4. It can also happen as a complication after a lung or stem cell transplant
Some medications can cause severe adverse reactions leading to bronchiolitis obliterans
It's essential to diagnose and get proper treatment. Make sure not to neglect or leave untreated as it can lead to death.
Types of Bronchiolitis in Adults
Respiratory Bronchiolitis
Causes: Respiratory bronchiolitis is mainly caused in adults due to smoke. It can also be caused by occupational or industrial fumes and chemicals.
Management: It can be managed by avoidance of further exposure to the causative agent, i.e., smoke. Keep away from both 1st hand and 2nd hand cigarette smoke.
Prognosis: This disease in itself is not associated with respiratory failure. In some cases, respiratory bronchiolitis is present in conjunction with Interstitial lung disease and is called respiratory bronchiolitis-associated interstitial lung disease. These disorders can result in respiratory failure.3
Acute Bronchiolitis
Causes: It is usually caused by respiratory viruses and is common in young children and infants. This is the leading cause of hospitalization in infants.
Management: At-home supportive care is essential in mild cases. Ensure proper fluid intake to prevent dehydration. For nasal blockage, saline drops and suction through a bulb syringe is done before feeding and sleeping.
In moderate and severe cases, hospitalization is required in which oxygen therapy, corticosteroids, antibiotics, and bronchodilators are needed.
Prognosis: Acute Bronchiolitis is managed well with supportive care and only in severe cases leads to hospitalization.3
Constrictive/ Obliterative Bronchiolitis
Causes: Inhalation of chemicals such as diacetyl from microwave popcorn flavoring or coffee beans processing are associated with the development of obliterative Bronchiolitis. Some rare reasons are drugs and infections.
Management: Bronchiolitis Obliterans is a chronic and irreversible disease. But early detection and medications can stop the worsening of the condition. First, reduce exposure to chemicals.
Corticosteroids are given to inhibit inflammation which suppresses the immune system. Inhaler or inhaled medications are prescribed. Oxygen therapy is done to increase oxygen levels.
Lung transplantation is rarely needed but only for patients who do not respond to medications.
Prognosis: The prognosis of bronchiolitis obliterans is not good. Despite treatment with corticosteroids, and macrolide therapy, it may result in respiratory failure and eventually death. It happens in patients with solid organs or connective tissue disorder.3
Follicular Bronchiolitis
Causes: Follicular Bronchiolitis is caused by connective tissue disease, infections, and immunodeficiency disorders.
Management: Treated by managing the underlying disease, i.e., connective tissue disease or immunodeficiency disorder.
Prognosis: The prognosis of follicular bronchiolitis depends on the underlying disease. Mostly it doesn't lead to any morbidity and mortality.3
Diffuse Aspiration Bronchiolitis
Causes: This is caused in middle-aged and older individuals due to the presence of risk of aspiration like neurological disorder or Gastroesophageal reflux disease (GERD).
Management: It is treated by managing GERD through anti-gastroesophageal reflux measures.
Prognosis: Diffuse aspiration Bronchiolitis is not associated with respiratory failure if its diagnosis is timely and managed correctly.3
Diffuse Panbronchiolitis
It is an unusual form mostly present in the Asian population (Japanese).
Management: Macrolide therapy is done.
Prognosis: Before macrolide therapy, diffuse panbronchiolitis had a poor prognosis resulting in respiratory dysfunction and recurrent infections. Many patients presented with respiratory failure within five years of diagnosis. But after macrolide therapy, positive outcomes have been seen. The 10-year survival rate has risen to 90 percent.3
Mineral Dust Airway disease
Causes: This is caused by inhaling inorganic dust like silica, silicate, iron oxide, aluminum oxide, coal , talc, etc. This disease is occupational-related.
Management: It is managed by avoidance of additional exposure to occupational chemicals.
Prognosis: Its prognosis is good. It's diagnosed through lung biopsy and doesn't lead to any morbidity if further exposure is avoided.3
Diagnosis
Initially, doctors will diagnose the disease with physical signs and symptoms. But some tests are also conducted to analyze:
- A chest X-ray is done to rule out the possibility of a lung disease called Pneumonia
- Blood sample
- Mucus is taken through the swab to test the type of virus present, such as a respiratory syncytial virus.
To diagnose bronchiolitis obliterans, the following tests can be performed:
- Chest X-ray
- Mucus swab
- Spirometry to check how much and how quickly oxygen is taken into the lungs
- Lung biopsy
Treatment
There is no specific medication for the treatment of Bronchiolitis Obliterans. However, rest and proper fluid intake are necessary.
- Corticosteroids are taken to reduce inflammation and clear up the mucus
- Don't neglect fluid intake. Keep yourself hydrated.
- Take oxygen therapy to ease breathing
- Immunosuppressant medications help regulate the immune system
- Try to do breathing exercises and reduce stress to relieve breathing problems
- In severe cases, a lung transplant is the best option.
Keep your home free from smoke and use a humidifier in the room to keep the air moist.2
Prevention
Some steps are done to prevent Bronchiolitis Obliterans:
- Avoiding exposure to toxic chemicals
- Washing hands regularly to avoid respiratory illnesses
- Avoid contact with sick people or respiratory diseases that can quickly spread through coughing and sneezing.
Summary
Bronchiolitis is an inflammatory disease affecting small airways called bronchioles. It's different from bronchitis as bronchitis is caused by inflammation of large airways.
Adults are often affected by bronchiolitis obliterans, which occurs due to exposure to chemicals or as side effects of lung or stem cell transplant.
Bronchiolitis in adults has different types, i.e., constrictive obliterans, follicular Bronchiolitis, diffuse aspiration bronchiolitis, and diffuse panbronchiolitis.
Corticosteroids, antibiotics, and immunosuppressive medications are treatments of choice. Early diagnosis and treatment are essential as any neglect in treatment may lead to harmful results, even death.
References:
1. Justice NA, Le JK. Bronchiolitis. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 [cited 2022 Aug 31]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK441959/
2. Bronchiolitis symptoms, causes, and risk factors [Internet]. [cited 2022 Aug 31]. Available from: https://www.lung.org/lung-health-diseases/lung-disease-lookup/bronchiolitis/symptoms-diagnosis-treatment
3. Bronchiolitis(Respiratory bronchiolitis, acute bronchiolitis, constrictive or obliterative bronchiolitis, follicular bronchiolitis, diffuse panbronchiolitis, diffuse aspiration bronchiolitis, mineral dust airway disease) [Internet]. Pulmonology Advisor. 2019 [cited 2022 Aug 31]. Available from: https://www.pulmonologyadvisor.com/home/decision-support-in-medicine/pulmonary-medicine/bronchiolitis-respiratory-bronchiolitis-acute-bronchiolitis-constrictive-or-obliterative-bronchiolitis-follicular-bronchiolitis-diffuse-panbronchiolitis-diffuse-aspiration-bronchiolitis-mineral/
