Respiratory ilnesses in infants

Question 1

Laryngotracheitis / subglottic laryngitis (croup, pseudocroup)

Answer 1

■ “Croup” caused by diphtheria, “pseudocroup” caused by parainfluenza
virus but this is so common that people normally just call it “croup” too

■ Affects kids 6 months to 3 years with “barky” seal-like cough,
inspiratory stridor, hoarse voice.

■ Dx: clinical. Can confirm with steeple sign on X-ray

■ Treatment :
● Mild: give humidified O2 +/- steroids (per rectum)
● Moderate/severe: the above + racemic nebulized epinephrine
○ Intubate if respiratory failure

Question 2

Epiglottitis

Answer 2

■ Caused by H. influenzae type B, rare due to vaccination
■ S/S: drooling, dysphagia, stridor, respiratory distress, high fever
■ Dx: clinical. Can confirm with thumbprint sign on CXR
■ Tx: airway management, O2, possibly nebulized epinephrine, steroids,
antibiotics

Question 3

Bronchiolitis

Answer 3

■ Caused by RSV, usually in child < 2 y/o during winter
■ S/S: wheezing, respiratory distress (if very young then maybe apnea),
recent history of nasal congestion/discharge/cough
■ Dx: clinical.
■ Tx: supportive. Admit to hospital mostly only for reassurance. Can provide O2 and fluids. Allowed to attempt salbutamol one time, but does not affect the course of the illness. Intubate if becomes critical.

Question 4

Infectious mononucleosis:

Answer 4

○ Pathogens: usually EBV. Sometimes CMV or other viruses (HIV, HHV-6,adenovirus) or toxoplasmosis.

○ S/S: fever, tonsillitis/pharyngitis +/- exudates, significant fatigue.
■ Lymphadenopathy: posterior or diffuse cervical lymph nodes
■ +/- Hepatosplenomegaly (with hepatitis)
■ +/- rash after amoxicillin

○ Dx: monospot/heterophile Ab test (Paul Bunnel) agglutination assay.
Lymphocytosis with atypical Downey cells seen on lab slide

○ Tx: supportive. Avoid contact sports, risk of splenic rupture. Avoid ß-lactam
antibiotics, may cause rash.