Childhood Respiratory Disorders MCQs

RISK FACTORS FOR ASTHMA IN CHILDHOOD Parental asthma Allergy: Atopic dermatitis (eczema) Allergic rhinitis Food allergy Inhalant allergen sensitization Food allergen sensitization Severe lower respiratory tract infection: Pneumonia Bronchiolitis requiring hospitalization Wheezing apart from colds Male gender Low birthweight Environmental tobacco smoke exposure Reduced lung function at birth Out of all this, only Smoking exposure is environmental factor Tags : Topic : ASTHMA Difficulty level : MUST KNOW PYQ : INICET NOV 2022; AIIMS JULY 2020 Reference : Nelson textbook of pediatrics, 21 st ed., pg. 1189

RISK FACTORS FOR BRONCHIOLITIS Parents who smoke Siblings attending day care or school (risk of transmitting viral infections) Chronic lung disease due to prematurity Breastfeeding given for Tags : Topic : BRONCHIOLITIS Difficulty level : GOOD TO KNOW PYQ : FMGE AUG 2020 Reference : Nelson textbook of pediatrics, 21 st ed., pg. 2217

The child has recurrent upper and lower respiratory tract infections suggesting CF. The sweat chloride test can yield falsely low values, so the next step would be to perform DNA testing to identify any of the common CFTR mutations. Negative sweat chloride test results do not exclude CF. Reference: Nelson textbook of pediatrics, 1 st SA ed., pg. 2104

Explanation: Cystic fibrosis is caused by a CFTR gene mutation leading to defective chloride transport across epithelial cells. The sweat chloride test is the gold standard diagnostic test , with chloride levels ≥60 mmol/L being diagnostic. It directly measures abnormal electrolyte transport and is the most reliable confirmatory tool despite genetic testing. Explanation of other options: Lung biopsy (Option B): Rarely used; invasive and not diagnostic for CF. Used mainly for histopathology in other lung diseases. Chest X-ray (Option C): May show bronchiectasis or hyperinflation, but findings are nonspecific and cannot confirm CF. Nasal swab culture (Option D): Identifies infections like Pseudomonas , but is not confirmatory for CF diagnosis.

More than 95% of males with cystic fibrosis are azoospermic because of failure of development of wolffian duct structures, but sexual function is generally unimpaired. Many male patients with Cystic Fibrosis have an abnormality called CAVD= Congenital Absence of Vas Deferens. This contributes to azoospermia and infertility in males Please note that female fertility may be reduced due to thick cervical mucus but there is no structural issues of reproductive tract in female patients with Cystic Fibrosis Reference: Nelson textbook of Pediatrics, 20 th ed., pg. 2104

Cystic fibrosis has defective CFTR gene on 7q31.2. It is autosomal recessive. Mutation most common is Del 508 phenylalanine for the Chloride channel. Previously it was called as Delta F 508 Mutation. Reference: Nelson textbook of Pediatrics, 20 th ed., pg. 2098

Bronchiolitis obliterans (BO) is an uncommon form of obstructive lung disease that occurs as a result of a severe insult to the small airways and ultimately leads to fibrosis and obliteration of the bronchioles. Epidemiology studies suggest that BO occurs frequently in children of Asian and South American descent. In children, the leading cause of BO is infectious, with adenovirus being the most common offending agent. BO also occurs in patients with lung or bone marrow transplants (BMTs) and in those with autoimmune disorders. Other causes include toxic inhalation injury or aspiration, hypersensitivity pneumonitis, drug toxicity, and Stevens-Johnson syndrome, SJS. Reference: Rudolph's Pediatrics 23 rd Ed/Chapter 508

This girl has recurrent pulmonary infections. The presence of P aeruginosa on a sputum sample strongly suggests the diagnosis of CF. Patients with CF have a high prevalence of colonization with P aeruginosa, Staphylococcus aureus, and Burkholderia cepacia. The innate defenses of the airway epithelium cells of CF patients may be compromised, making them unable to fight these organisms. Reference: Nelson textbook of pediatrics, 1 st SA ed., pg. 1414