PNP-PC acute pediatric illness: fever, respiratory infections, and emergency recognition

Fever definition: temperature ≥38°C (100.4°F) rectal in infants; axillary ≥37.4°C. Rectal temperature is the most accurate in infants <3 months.

Age-based fever risk stratification:

• <28 days (neonate): All fevers require emergency evaluation — admit for sepsis workup (CBC, blood culture, urine culture via catheter, CSF, CXR), empirical antibiotics (ampicillin + gentamicin ± acyclovir for HSV). Risk of serious bacterial infection (SBI) 10–15%.
• 29–60 days: High-risk vs. low-risk stratification (Rochester/Philadelphia criteria — WBC, UA, clinical appearance). Low-risk well-appearing infants may be managed with close outpatient follow-up in select centres, but most recommend admission. Risk SBI ~5–8%.
• 2–3 months: Well-appearing, immunised infants with low-risk labs may be managed outpatient with 24-hour follow-up. Unimmunised or ill-appearing → full sepsis evaluation.
• 3–36 months: Well-appearing with no source identified — viral illness most likely. Occult bacteraemia risk markedly reduced by pneumococcal vaccine (PCV13). Clinical assessment is paramount — "toxic" appearance mandates evaluation regardless of temperature.

Fever antipyretics: Acetaminophen 15 mg/kg q4–6h; ibuprofen 10 mg/kg q6–8h (avoid <6 months). Goal: comfort, not normalisation of temperature. Fever is protective. Do NOT alternate antipyretics routinely — increases dosing error risk. Aspirin contraindicated in children (Reye syndrome risk).

Bronchiolitis (most common lower respiratory tract infection in infants <2 years): RSV most common (winter seasonal). Clinical: rhinorrhoea → wheeze, tachypnoea, subcostal retractions, crepitations, SpO2 may decrease. Diagnosis: clinical. Management: supportive — nasal suctioning, hydration, supplemental O2 if SpO2 <90%. No routine bronchodilators, no steroids, no antibiotics. Hospitalise: SpO2 persistently <90%, severe retractions, poor feeding, apnoea, very young (<3 months).

Pneumonia differentiation: Bacterial (fever >38.5°C, ill-appearing, focal exam findings, elevated WBC) vs. viral (gradual onset, diffuse findings, prominent URI symptoms). Atypical (walking) pneumonia (Mycoplasma) common in school-age children — insidious onset, nonproductive cough, bilateral patchy infiltrates. Treatment: amoxicillin 90 mg/kg/day for typical CAP; azithromycin for atypical. CXR not required for outpatient pediatric CAP if clinical diagnosis clear. Hospitalise: SpO2 <90%, moderate-severe respiratory distress, complicated pneumonia, or unable to tolerate oral medications.

Croup (laryngotracheobronchitis): Parainfluenza virus. Ages 6 months – 3 years. Barking seal-like cough, inspiratory stridor, hoarseness, low-grade fever. Worse at night. Steeple sign on AP neck X-ray (not required for diagnosis). Management: dexamethasone 0.6 mg/kg × 1 dose (mild-moderate — most cases); racemic epinephrine nebulisation for moderate-severe; oxygen as needed. Observe 3–4 hours after epinephrine (rebound stridor can occur).