352.2 🩺 國考版

352.2.1 高頻考點

352.2.1.1 Celiac Disease Genetics

  • HLA-DQ2 (95%) or HLA-DQ8 (5%) — necessary
  • 1% prevalence in Caucasian/European
  • 0.5% in Asian (increasing)
  • Family: 10x risk

352.2.1.2 Celiac Serology

  • Anti-tTG IgA (preferred screen)
  • Total IgA — rule out deficiency
  • If IgA deficient: anti-tTG IgG, anti-DGP IgG
  • EMA confirmatory
  • Anti-gliadin (older, less specific)

352.2.1.3 Celiac Duodenal Biopsy

  • Gold standard
  • 4-6 samples distal duodenum + bulb
  • Marsh classification 1-3c
  • Villous atrophy + crypt hyperplasia + IEL
  • Must be on gluten diet for testing

352.2.1.4 Celiac Treatment

  • Lifelong strict gluten-free diet (GFD)
  • Avoid wheat, barley, rye
  • Oats acceptable (cross-contamination risk)
  • < 20 ppm gluten in “gluten-free” labeled
  • Dietitian guidance

352.2.1.5 Dermatitis Herpetiformis

  • Pathognomonic for celiac
  • Pruritic vesicular eruption
  • IgA deposits at dermal papillae
  • Dapsone + GFD

352.2.1.6 Associated Conditions

  • T1DM (5-10% have celiac)
  • Autoimmune thyroid
  • IgA deficiency
  • Down + Turner syndromes
  • PBC, autoimmune hepatitis
  • Sjögren

352.2.1.7 Refractory Celiac

  • Persistent symptoms + histology > 12 months
  • Type I (no clonal IEL) vs Type II (clonal IEL — EATL risk)
  • Budesonide, IS, biologics

352.2.1.8 Non-Celiac Gluten Sensitivity

  • Symptoms without celiac/wheat allergy
  • Diagnosis of exclusion
  • Lower-FODMAP gluten products may help

352.2.1.9 Tropical Sprue

  • Tropical regions
  • Tetracycline + folate + B12

352.2.1.10 Whipple Disease

  • T. whipplei
  • Multisystemic
  • PAS+ macrophages
  • IV ceftriaxone → TMP-SMX 1 year

352.2.1.11 SIBO

  • Diabetic, scleroderma, post-surgery, achlorhydria
  • Hydrogen breath test
  • Rifaximin 550 TID × 14 days
  • Recurrent: re-treatment + underlying

352.2.1.12 Lactose Intolerance

  • Primary: Asians, Africans, Native Americans
  • Secondary: post-enteritis, celiac
  • Hydrogen breath test
  • Avoidance + Lactaid

352.2.1.13 Pancreatic Insufficiency

  • Fecal elastase < 200 ÎŒg/g
  • PERT (pancrelipase) with all meals
  • ADEK vitamins

352.2.2 易混淆比范

Disease Diagnosis Treatment
Celiac Anti-tTG IgA + biopsy GFD lifelong
Tropical sprue Tropical area Tetracycline + folate
Whipple PAS+ macrophages, PCR Ceftriaxone → TMP-SMX
SIBO Hydrogen breath test Rifaximin
Lactose intolerance Hydrogen breath test Avoidance + Lactaid
Pancreatic insufficiency Fecal elastase PERT + ADEK

352.2.3 Special Topics

352.2.3.1 EATL (Enteropathy-Associated T-Cell Lymphoma)

  • Rare complication of celiac
  • T-cell lymphoma
  • Type II refractory celiac
  • Chemotherapy + autologous SCT

352.2.3.2 Dermatitis Herpetiformis Mechanism

  • IgA against epidermal transglutaminase
  • Dapsone + GFD
  • Strict GFD may eventually allow dapsone discontinuation