Source / episode info

• **Episode:**130
• **Title:**Divine Intervention Episode 130 – USMLE Step 2CK Rapid Review Series 10 (Peds)
• **Published:**2019-07-31
• Source:Episode page

One-liner

This episode reviews key pediatric topics including Croup/Epiglottitis differentiation based on airway signs, neonatal bowel obstruction differentials (volvulus vs. atresia), malabsorption workup for celiac disease, differentiating nephritic syndromes (IgA vs. post-strep), and recognizing the classic presentations of major immunodeficiency disorders like CGD, IgA deficiency, and Wiskott-Aldrich syndrome.

High-yield summary

• Croup: Caused by Parainfluenza virus; presents with a "barking" cough and stridor; is an upper airway problem (subglotic); classic radiographic finding is the steeple sign.
• Neonatal Bowel Obstruction: The differential includes Malrotation with Volvulus, Duodenal Atresia (classic double bubble), and Jejunal/Ileal Atresia (often associated with triple bubbles).
• Celiac Disease: Malabsorption leads to deficiencies in fat-soluble vitamins (A, D, E, K) and can cause secondary hyperparathyroidism. The diagnostic hallmark is the presence of anti-tissue transglutaminase antibodies.
• Nephrotic Syndrome Complications: Due to massive proteinuria (>3.5 g/24h) leading to loss of anticoagulant proteins (e.g., Antithrombin III), patients are highly prone to thrombosis, particularly renal vein thrombosis (RVT).
• Immunodeficiency Triads: Recognize the classic associations: CGD -> Aspergillus infections; IgM Deficiency -> recurrent bacterial infections (encapsulated organisms); Wiskott-Aldrich Syndrome -> triad of thrombocytopenia, eczema, and immunodeficiency.
• Nephritic vs. Nephrotic: Remember that IgA nephropathy typically presents with hematuria/glomerulonephritis shortly after an URI (1–3 days), while post-streptococcal GN occurs 2–6 weeks later.

Learning objectives

• Differentiate the clinical presentation and pathophysiology of Croup vs. Epiglottitis.
• Apply imaging principles to differentiate between duodenal, jejunal, and malrotational bowel atresia in neonates.
• Recognize the key diagnostic antibodies (e.g., anti-tTG) and associated deficiencies in celiac disease.
• Differentiate the timing and clinical features of IgA nephropathy versus post-streptococcal glomerulonephritis.
• Correlate specific immune deficiency syndromes with their characteristic infections, skin findings, or lab abnormalities.