BRONCHIOLITIS

The patient in question is presenting with features of bronchiolitis obliterans.

Bronchiolitis obliterans is a small airway disease that is histologically charecterised by proliferation of fibrous tissue in the bronchiolar walls.

It produce irreversible airway obstruction.

Clinical features: wax and wane in between. Most common symptoms are fever, cough with sputum, dyspnea with wheeze.

Investigation: Xray shows hyperlucent lung, Pulmonary function testing shows obstructive pattern.

Ref: Severe asthma: pathogenesis and clinical management By S. J. Szefler, Donald Y. M. Leung page 288; Imaging in Pediatric Pulmonology By Robert Cleveland page 237.
3. Pediatric Chest Imaging: Chest Imaging in Infants and Children By Javier Lucaya page 108; Imaging of the newborn, infant, and young child By Leonard E. Swischuk page 122.

Description:

Bronchiolitis refers to inflammation of the bronchioles. It is commonly found in infants and children and is caused by respiratory syncitial virus or adenovirus. Children presents with insidious onset of cough and dyspnea.

PFT shows irreversible airflow obstruction.

Bronchiolitis obliterans is a rare chronic obstructive lung disease characterized by complete obliteration of the small airways following a severe insult.

The most common form in children is postinfectious, following a lower airway tract infection with adenovirus, although influenza, rubeola, Bordetella, and Mycoplasma are also implicated.

Ans. is ‘a’ i.e., RSV (respiratory syncytial virus) [Ref Ananthnarayan 9^th/e p. 510 & 8^th/e p. 508; Jawetz 23’/e p. 558] Respiratory syncytial virus is the most important cause of lower respiratory tract illness in infants and young children, usually outranking all other microbial pathogens as the cause of bronchiolitis and pneumonia in infants under 1 year of age –

Respiratory svncvtial virus (RSV)

. Member of Paramyxoviridae family -4 Enveloped RNA virus.

.  Differences from other paramyxoviruses:

– RSV does not possess hemagglutinin activity

– RSV does not have neuraminidase or hemolytic properties.

– Nucleocapsid is smaller than other paramyxoviruses.

.  Characterised by production of giant cells and syncytial formation.

Ans. is ‘b’ i.e., Mumps causes septic meningitis in adult 

.  There is no need to read any text book for this question, just read option ‘b’ carefully.

.  Viruses cause aseptic meningitis (not septic).

.   Septic meningitis is caused by bacteria.

.   Aseptic menigitis and orchitis are the most common complications of mumps in adult. About other options:

.   RSV is the most common cause of bronchiolitis.

.   SSPE is one of the neurological complication of measles.

.   Pneumonia with pleural effusion can be caused by EBV.

Ans. is ‘a’ i.e., RSV-Bronchiolitis; ‘b’ i.e., Orf – viral infection transmitted from sheep

Ans. is ‘b’ i.e., Ribavirin

Ribiavirin is the standard treatment for RSV bronchiolitis in infants and children.

Ans. is ‘d’ i.e., Respiratory syncytial virus

“The most common etiological agent for Bronchiolitis is Respiratory synctial virus. RSV is responsible for more than 50% of cases of bronchiolitis.”

Bronchiolitis

o Bronchiolitis is the most common serious acute lower respiratory tract infection in infants and young children. o Most vulnerable group is between the ages of 1 and 6 months.

o But the disease can affect children up to 2 years.

o More common in males.

Organisms causing bronchiolitis

o Bronchiolitis is predominantly a viral disease.

i) RSV (most common)                       ii) Parainfluenza virus 3, 1, 2             v) Mycoplasma pneumoniae

iii) Adenovirus                                 iv) Influenza virus

Ans. is ‘a’ i.e., Caused by respiratory syncytial virus, ‘b’ i.e., Hyperinflation of the chest

o Bronchiolitis is caused most commonly by RSV.

o Major concerns, include not only the acute effects of bronchiolitis but also the possible development of chronic airway hyperreactivity, i.e. asthma.

Ans. is `a’ i.e., Bronchiolitis

Clinical manifestations of hronchiolitis

o The usual course of disease is 1-2 days of —> Fever, Rhinorrha, Cough

o This is followed by –

• Wheezing                          
• Tachypnea                        
• Breathing pattern is shallow
• Cyanosis                                    
• Nasal flaring                    
• Rales, crepitation and ronchi
• Respiratory distress —> retraction of intercostal space & suprasternal notch.

o Liver and spleen are pushed downward because the hyperinflated emphysematous lungs push the diaphragm downward.

o Anteroposterior diameter of chest is increased and hyperresonance is noted on percussion.

o The leukocyte count is normal or slightly elevated.

Chest X-ray

o Hyperinflation of the lung         o Diaphragm is pushed down           o Lung fields are abnormally translucent.

Ans. is ‘a’ i.e., Ribavirin

The treatment of Bronchiolitis is essentially symptomatic and drug treatment is usually not indicated.

Ans. is ‘a’ i.e., RSV

Ans. is ‘c’ i.e., Chest X-ray shows the hyperinflation bilaterally

Ans. is ‘a’ i.e., Caused by R.S.V.; ‘b’ i.e., Wheeze present

Ans. is `d’ i.e., Bronchiolitis obliterans

Bronchiolitis obliterans

o Bronchiolitis obliterans. is a rare chronic lung disease of the bronchioles and smaller airways.

o Bronchiolitis obliterans most commonly occurs inpediatric population after respiratory infections (i.e. adenovirus, mycoplasma, measles, influenza, pertussis).

o Other causes include connective tissue disease (i.e. juvenile rheumatoid arthritis, systemic lupus erythematosis, scleroderma)

o Bronchiolitis occurs in all age groups.

Pathogenesis

o After the initial insult, inflammation affecting terminal bronchioles, respiratory bronchioles and alveolar ducts may result in obliteration of the airway lumen.

o Epithelial damage resulting in abnormal repair is characteristic of bronchiolitis obliterans.

• Complete or partial obstruction of the airway lumen may result in air trapping or atelactasis. Clinical manifestations
• Cough, fever, cyanosis and respiratory distress followed by initial improvement may be the initial signs of bronchiolitis obliterans.

o Progression of the disease may ensue with increasing dyspnoea, cough, sputum production and wheezing.

o Chest radiographs may be relatively normal compared with the extent of physical findings but may demonstrate hyperluscency and patchy infiltrates (occasionally, a swyer James syndrome, i.e. a unilateral hyperluscent lung has developed).

o Pulmonary function tests demonstrate varaible findings but typically shows signs of airway obstruction.

o Ventilation perfusion scan shows a typical motheaten appearance of multiple matched defects in ventilation and perfusion.

o CT scan demonstrates patchy areas of hyperluscency.

o Open lung biopsy or transbronchial biopsy remains the best means of establishing the diagnosis of bronchiolitis obliterans.

Treatment

o No definite therapy exists for bronchiolitis obliterans.

o Administration of corticosteroids may be beneficial

About other options

Follicular bronchitis

o It is a lymphoproliferative lung disorder characterized the presence of lymphoid follicles, coursing along the airways (bronchi or bronchioles)

o It is rare in children.

o Although the cause is unknown, an infectious aetiology has been proposed.

o Onset of symptoms generally occurs by 6 weeks of age and peaks between 6 and 18 months. o Cough, moderate fever and fine crackles are common clinical findings.

o Fine crackles generally, persist over time and recurrence of symptoms is common.

o Chest radiographs may be relatively benign initially but evolve into the typical interstitial pattern. o Pulmonary function tests show restrictive pattern

o Chest CT shows fine reticular pattern.

Open lung biopsy is used to make definitive diagnosis.

Pulmonary alveolar microlithiasis

o This is a rare disorder.

o Although the underlying cause of pulmonary alveolar microlithiasis is unknown, the disease is characterized by the formation of lamellar concretions of calcium phosphate or “microlith”, within the alveoli, creating a classic pattern on the radiograph.

o Chest radiography typically reveal bilateral infiltrates with a fine sandlike micronodular appearance.

o Although the mean age at the time of diagnosis is in the mid 30s the onset of the disease can occur during childhood.

• When symptomatic, individuals with pulmonary alveolar microlithiasis usually complain of dyspnoea on exertion and non productive cough.

o Physical examinations of the lungs may reveal fine inspiratory crackles and diminished breath sounds. Clubbing occurs, although this is usually a more advanced sign.

o Children are often asymptomatic on initial presentation.

Diagnosis

o Chest radiography typically reveals b/L infiltrate with a fine sandlike micronodular appearance or “Sandstorm” appearance.

o CT scan shows diffuse micronodular calcified densities.

o Open lung biopsy reveals laminated calcific ioncretions within the alceoli.

Ans. is ‘d’ i.e., Bronchiolitis

Ans. is ‘b’ i.e., It occurs commonly in children above 2 years of age

A i.e. Sarcoidosis; B Histoplasmosis; C i.e. Tuberculosis

Answer is A (Bronchiolitis obliterans):

The patient in question is presenting with charachteristic features of bronchiolitis obliterans.

Fever, cough, and wheeze are common clinical features of bronchiolitis obliterans and a period of initial improvement may well be seen in cases of bronchiolitis obliterans (Initial sign of B.0).

Hyperluscency or chest X-Ray and obstructive curve on pulmonary function tests furthur suggest the diagnosis of bronchiolitis obliterans.