A Review of Childhood Lung Conditions for the Physician Assistant Exam
The Physician Assistant Exam (PANCE) will expect you to understand that lung conditions that affect adults are not the same as the ones that affect the pediatric population. Kids have smaller airways, and their respiratory muscle structure is less developed. Pediatric conditions include croup, epiglottitis, respiratory syncytial virus (RSV), and whooping cough.
A barking cough: Croup
Most people who have children or have worked with children are aware of the sound of a croup cough. It’s a distinct sound, almost like the barking of a seal. Croup can affect the upper airways, especially the larynx and trachea. That’s why another term for croup is laryngotracheobronchitis.
Croup is common in very young children. You can see it in children as young as 5 to 6 months and as old as 3 to 4 years. The cause of croup is usually viral, and the most common cause is parainfluenza. Note that croup can be caused by other viruses, such as the influenza virus and rhinovirus, the commonest cause of the common cold.
A child can present with typical upper respiratory infection symptoms, but as the inflammation of the upper airway gets worse, you begin to hear stridor, a high-pitched wheeze that’s worse on inspiration. The child is also likely to have a mild fever. The croup symptoms tend to worsen at night. Other symptoms can include hoarseness and significant accessory muscle use, as well as signs of cyanosis.
Kids like to put anything and everything in their mouths, so make sure you rule out other causes of upper airway obstruction, such as a foreign body or a big epiglottis. Use a radiograph to check the out the lungs and the cervical soft tissues of the neck.
The treatment is paying attention to the ABCs and stabilizing the airway, if needed. The hallmark of treatment is humidified oxygen. In the hospital, so-called croup tents can be used.
Epiglottitis is an inflammation of the epiglottis, causing it to enlarge (swell), which can obstruct the child’s small airways. It’s usually caused by a bacterial infection, namely Haemophilus influenzae type B. Epiglottitis affects younger children, usually between ages 2 and 6, although it may occur in older children. Vaccination has greatly diminished the occurrence of epiglottitis.
Children may present with an upper respiratory infection that quickly worsens, with hypoxemia, tachypnea, and accessory muscle use. Kids with epiglottitis are pretty toxic looking; they can be drooling and sitting upright, often in a sniffing position, with their head and nose tilted forward and upward as if smelling something. On physical examination, you see an erythematous, edematous, angry-looking epiglottis.
Although epiglottitis and croup can be similar in presentation, there are differences. Epiglottitis can worsen a lot faster than croup. Stridor may be present in epiglottis, but the barking cough of croup is not. A cervical soft tissue radiograph also shows a swollen epiglottis in epiglottitis.
Epiglottitis is an emergency that needs to be recognized swiftly. If the epiglottis gets too swollen, it can completely block the airway, creating a potentially life-threatening situation. So the treatment for epiglottitis is first to stabilize the airway. If intubation is needed, you want to avoid the trauma of repeat intubations and intubation attempts; they can compromise an already swollen airway. Intravenous antibiotics need to be administered as well.
Respiratory syncytial virus (RSV)
Respiratory syncytial virus (RSV) can cause upper respiratory infection symptoms in very young children. People at high risk for RSV include babies of several months and those who are premature or immunocompromised in some way.
In most cases, RSV will run its course, and supportive measures are needed. Sometimes, however, the virus is bad enough that the child can become symptomatic. RSV is the leading cause of bronchiolitis in children
In certain patients, RSV can affect the lower airways, cause inflammation of the bronchioles, and increase the risk of developing pneumonia.