â– LECTURE OVERVIEW: Inflammatory Bowel Disease (IBD) is a chronic, relapsing inflammatory disorder of the GI tract, classically divided into Crohn's Disease and Ulcerative Colitis (UC).
â– MORPHOLOGIC AND HISTOPATHOLOGIC PROFILES:
1. Crohn's Disease (Transmural, Patchy):
- Distribution: Can affect any part of the gastrointestinal tract from mouth to anus, characteristically displaying 'skip lesions' (normal mucosa separating inflamed areas).
- Depth: Transmural inflammation (invading the entire bowel wall), leading to fistulas, stricture-induced obstructions, and deep aphthous ulcers.
- Histology: Characterized by non-caseating granulomas and mucosal cobblestoning.
2. Ulcerative Colitis (Mucosal, Continuous):
- Distribution: Confined strictly to the colon and rectum, spreading continuously proximally from the rectum.
- Depth: Confined strictly to the mucosa and submucosa.
- Histology: Shows crypt abscesses with neutrophils and pseudo-polyps.
â– PROFESSOR'S ADVANCED PATHOPHYSIOLOGY:
The cellular cascade undergoes active remodeling in response to sustained stressors. Intracellular signalling involves key phosphorylation tracks and secondary lipid messengers, culminating in altered gene transcription and structural adaptations in target tissues.
â– PEDIATRIC CONTEXT & CONTINGENCIES:
Developing cohorts present with high body-water percentages and dynamic hepatic enzyme maturation pathways.
[HY-BOARD-1141]
🌟 Dynamic Clinical Key:
On radiography, chronic Ulcerative Colitis presents with a loss of haustra, creating a classic 'lead-pipe' colon. Crohn's disease presents with a 'string sign of Kantor' on barium swallow due to stricture-induced narrowing of the terminal ileum. Assess patient clearance profiles (creatinine clearance and LFTs) before starting multi-drug regimens to avoid severe toxic accumulation. Always utilize body-surface-area or weight-based dosing calculators for pediatric populations.