Side-by-side tables of the look-alike pediatric conditions the exam deliberately confuses, each ending with the single clue that separates them.
| Condition | Picture | Clue / X-ray | Action |
|---|---|---|---|
| Viral croup (parainfluenza) | 6 mo–3 y, coryza then barking cough, hoarse, worse at night, non-toxic | Steeple sign (X-ray not needed) | Oral dexamethasone 0.15–0.6 mg/kg; nebulized adrenaline if stridor at rest |
| Spasmodic croup | Sudden nocturnal, afebrile, no prodrome, recurrent, atopic child | Resolves in hours | Reassure; treat as croup if needed |
| Epiglottitis (Hib, unimmunized) | Sudden high fever, toxic, drooling, tripod, muffled voice, no bark | Thumb sign | Do not examine throat or lie flat; airway in theatre, then ceftriaxone |
| Bacterial tracheitis (S. aureus) | Viral croup then high fever, toxic, brassy cough, can lie flat | No response to adrenaline; ragged tracheal margin | Intubation + anti-staph antibiotics |
| Retropharyngeal abscess | <5 y, fever, neck stiffness/refuses extension, drooling | Widened prevertebral soft tissue | CT, IV antibiotics ± drainage |
| Foreign body | Sudden choking, afebrile, 6 mo–3 y | Unilateral wheeze, air trapping | Rigid bronchoscopy |
Westley score (calculator) grades croup severity.
| Bronchiolitis | Asthma / viral wheeze | Pneumonia | Foreign body | |
|---|---|---|---|---|
| Age | <2 y (peak 2–6 mo) | Any; asthma usually >5 y | Any | 6 mo–3 y |
| Onset | Coryza 2–3 days, first episode | Recurrent, triggers, atopy | Fever, cough | Sudden choking |
| Chest | Wheeze + diffuse fine crackles | Bilateral wheeze, prolonged expiration | Focal crackles, bronchial breathing | Unilateral wheeze/↓air entry |
| Fever | Low/none | Usually none | High | None |
| Bronchodilator | No benefit | Responds | No | No |
| CXR | Not routine (hyperinflation) | Not routine | Consolidation | Air trapping on expiration |
| Treat | Supportive: O2 if SpO2 <90–92%, feeds | SABA, steroids | High-dose amoxicillin | Rigid bronchoscopy |
WHO tachypnea: <2 mo ≥60, 2–12 mo ≥50, 1–5 y ≥40/min.
| Cause | Discriminating clue | Test / action |
|---|---|---|
| Group A strep | 5–15 y, sudden fever, tender anterior nodes, exudate, palatal petechiae, no cough/coryza, ± sandpaper rash | RADT (culture if negative in children); penicillin V/amoxicillin 10 days |
| EBV mononucleosis | Adolescent, posterior cervical nodes, splenomegaly, fatigue, rash after amoxicillin | Atypical lymphocytes, Monospot (false-negative <4 y); no contact sports ≥3–4 wk |
| Adenovirus | Pharyngitis + conjunctivitis + fever | Supportive |
| Diphtheria | Unimmunized, grey adherent membrane that bleeds, bull neck | Antitoxin + erythromycin/penicillin |
| Herpangina (Coxsackie A) | Vesicles/ulcers on posterior palate | Supportive |
| HSV gingivostomatitis | Anterior ulcers + swollen bleeding gums | Oral acyclovir if early |
| Peritonsillar abscess | Trismus, uvula deviated away, hot-potato voice | Drainage + antibiotics |
McIsaac score (calculator) estimates GAS probability; in children it guides testing, not empirical treatment.