Pediatric Infectious Diseases and Immunology
Core concepts
Understand the approach to fever in the infant (age-based risk stratification, sepsis evaluation), common viral and bacterial infections, and the principles of antimicrobial stewardship. Know the vaccine-preventable diseases and the immunization schedule. Master the recognition of primary immunodeficiency (recurrent severe infections, failure to thrive, family history) and the interpretation of basic immune testing. Understand HIV, tuberculosis, and the approach to the child with recurrent fever.
Traps
Questions test whether you can distinguish a febrile infant under 3 months (full sepsis workup and empiric antibiotics) from an older child with a benign viral illness. Another trap is missing a serious bacterial infection in a child who looks well but has a high fever. Do not forget that not all recurrent infections indicate immunodeficiency - day care and anatomy matter.
Worked example
A 6-week-old with a temperature of 38.5°C requires a full sepsis evaluation (blood, urine, CSF cultures) and empiric antibiotics, regardless of how well the infant appears. The trap is discharging a young febrile infant because the examination is normal.
Rule of thumb
Age is the strongest predictor of serious bacterial infection in febrile infants; the younger the infant, the lower the threshold for full evaluation and empiric treatment.