352.4 📋 章末速蚘 Summary

352.4.1 🔑 䞀句話瞜結

Celiac disease = autoimmune enteropathy triggered by gluten in HLA-DQ2/DQ8 susceptible (necessary but not sufficient); ~ 1% Western, ~ 0.5% Asian (increasing)clinical spectrumclassic GI (diarrhea, malabsorption, weight loss, failure to thrive) + non-classic (iron deficiency anemia most common, osteoporosis, infertility, dermatitis herpetiformis pathognomonic with IgA deposits, neurologic ataxia/neuropathy, fatigue, depression, aphthous stomatitis, dental enamel) + silentassociatedT1DM (5-10% have celiac), autoimmune thyroid, IgA deficiency (need IgG-based serology), Down + Turner, PBC, AIH, Sjögrendiagnosisanti-tissue transglutaminase IgA (preferred screen) + total IgA + duodenal biopsy (gold standard — Marsh classification 1-3c with villous atrophy + crypt hyperplasia + IEL); on gluten diet for testingESPGHAN 2020 may avoid biopsy if high titer + EMA + HLA in select pediatrictreatmentlifelong strict gluten-free diet (GFD) — avoid wheat/barley/rye; dietitian; 70-80% histological + 90% symptom improvementrefractory celiacType I (no clonal IEL) vs Type II (clonal IEL — EATL risk); budesonide + IS + biologics + autologous SCTother malabsorption syndromes(1) mucosal (celiac, Crohn’s, tropical sprue — tetracycline + folate, Whipple disease — T. whipplei + PAS+ macrophages + IV ceftriaxone → TMP-SMX 1 year, AIDS enteropathy); (2) pancreatic insufficiency (chronic pancreatitis, CF, cancer) — fecal elastase < 200 + PERT + ADEK vitamins; (3) bile salt deficiency (cholestasis, ileal resection); (4) SIBO (small intestinal bacterial overgrowth) — diabetic enteropathy + scleroderma + post-surgery + achlorhydria; hydrogen breath test diagnosis + rifaximin 550 TID × 14 d treatment; (5) lactose intolerance — primary (Asians, Africans, Native Americans) + secondary; hydrogen breath test + avoidance + Lactaid + yogurt; 2024 emerging celiac therapieslatiglutenase + larazotide acetate + cell-based。

352.4.2 💊 治療粟芁

  • celiac treatmentlifelong strict gluten-free diet (GFD) — avoid wheat/barley/rye; oats acceptable (cross-contamination risk); < 20 ppm gluten labeled; dietitian guidance + support groups
  • dermatitis herpetiformisdapsone + strict GFD; may eventually allow dapsone discontinuation
  • refractory celiac type IIbudesonide + AZA + biologics + autologous SCT for EATL prevention/treatment
  • tropical spruetetracycline + folate + vitamin B12 supplementation
  • Whipple diseaseIV ceftriaxone × 2-4 weeks → oral TMP-SMX × 1 year; PCR + PAS+ confirms
  • pancreatic insufficiencyPERT (pancrelipase) with all meals (25,000-75,000 units lipase per meal) + ADEK vitamins supplementation
  • SIBOrifaximin 550 mg TID × 14 days first-line + alternatives (norfloxacin, metronidazole, cipro); re-treatment for recurrence; prokinetics + treat underlying motility/structural
  • lactose intolerancelactose restriction + Lactaid enzyme supplements + lactose-free dairy + yogurt with live cultures often tolerated
  • bile acid diarrheacholestyramine, colesevelam
  • short bowel syndromespecialized nutrition + teduglutide (GLP-2 analog) + TPN if severe

352.4.3 🎯 盧醫垫的考前提醒

  1. celiac HLA-DQ2 (95%) + HLA-DQ8 (5%) necessary but not sufficient — useful negative predictive value rules out; positive doesn’t confirm
  2. celiac serology workflowanti-tTG IgA (preferred screen) + total IgA; if IgA deficient → anti-tTG IgG or anti-DGP IgG; EMA confirmatory expensive
  3. celiac duodenal biopsy gold standardMarsh 1 (IEL) → Marsh 2 (+ crypt hyperplasia) → Marsh 3a-c (+ villous atrophy partial → subtotal → total); must be on gluten for valid testing
  4. dermatitis herpetiformis pathognomonic for celiacpruritic vesicular eruption + IgA deposits at dermal papillae; dapsone + GFD
  5. celiac associated conditionsT1DM (5-10% have celiac), autoimmune thyroid, IgA deficiency (need IgG-based serology), Down syndrome, Turner syndrome, PBC, AIH, Sjögren — screen if any
  6. refractory celiac Type II (clonal IEL)significant risk for EATL (enteropathy-associated T-cell lymphoma) — aggressive workup + treatment
  7. Whipple diseaseT. whipplei + multi-system (arthralgia + GI + neurologic + cardiac + ocular) + PAS-positive macrophages in lamina propria + PCR; IV ceftriaxone × 2-4 weeks → oral TMP-SMX × 1 year prevents relapse
  8. SIBO key risk factorsdiabetic enteropathy, scleroderma, post-bariatric surgery, Roux-en-Y, diverticula, Crohn’s, achlorhydria (PPI long-term), cirrhosis, elderly
  9. SIBO diagnosishydrogen breath test (lactulose or glucose) — most common; methane breath test for methanogens; jejunal aspirate gold standard but rarely done; treatment rifaximin 550 TID × 14 d
  10. lactose intolerance regional patternsprimary lactase deficiency (Asians, Africans, Native Americans, Hispanic — lactase persistence rare) vs secondary (post-enteritis, celiac, Crohn’s — may recover); hydrogen breath test + restriction + Lactaid