Celiac disease
Celiac disease is an immune-mediated small-intestinal enteropathy triggered by dietary gluten in genetically predisposed individuals, presenting with malabsorptive diarrhea, iron-deficiency anemia, or dermatitis herpetiformis. Diagnosis requires IgA tissue transglutaminase serology with a total IgA level while the patient still eats gluten, confirmed by duodenal biopsy showing villous atrophy, and the only treatment is a strict lifelong gluten-free diet.
- Topic reviewThe full article, organized the way the exam asks it.
- ABIM-format MCQsVignettes with an explanation for every wrong answer.
- Key factsThe numbers and thresholds worth memorizing, up front.
- AI tutorMedBrain answers the question you're stuck on.
What this article covers
- Overview
Definition: celiac disease is an immune-mediated enteropathy of the small intestine triggered by dietary gluten (the storage protein in wheat, rye, and barley) in genetically predisposed individuals.
- Epidemiology
Genetically restricted: essentially confined to HLA-DQ2/DQ8 carriers, with northern European descent an associated demographic.
- Risk factors
First-degree relative with celiac disease: the strongest identifiable risk factor given the HLA-linked genetic predisposition.
- Pathophysiology
Gluten exposure: ingested gliadin (the alcohol-soluble fraction of gluten in wheat, rye, and barley) resists complete digestion and reaches the small intestinal mucosa.
- Clinical features
Chronic diarrhea with malabsorptive features: the classic presentation, with bloating, weight loss, and steatorrhea from fat malabsorption; some patients present with constipation or dyspepsia instead.
- Differential diagnosis
Tropical sprue: presents identically with diarrhea and malabsorption but follows travel to or residence in the tropics; serology (tissue transglutaminase) is negative and small-bowel biopsy may show…
- Diagnosis
Confirm with serology plus duodenal biopsy while the patient is still eating gluten: the best initial test is IgA tissue transglutaminase (tTG-IgA) antibody with a total IgA level, because selective…
- Management
Refer to a knowledgeable registered dietitian and start a strict, lifelong gluten-free diet: the only effective treatment, requiring complete avoidance of wheat, rye, and barley, including in…
- Complications
Enteropathy-associated T-cell lymphoma: a moderately increased risk of small-bowel T-cell lymphoma is the most serious long-term complication, excluded by duodenal biopsy at diagnosis and considered in refractory or relapsing disease.
- Prognosis
Excellent with strict adherence: most patients have complete symptomatic and serologic resolution and normalization of villous architecture on a strict lifelong gluten-free diet.
- Prevention
Targeted serologic screening in high-risk groups: check IgA tissue transglutaminase antibody with total IgA in patients with type 1 diabetes mellitus, autoimmune thyroid disease, or a first-degree…
Read the whole article
Subscribing to Internal Medicine opens every article, the full question bank and MedBrain, on the web, iPhone and Android.
Related articles
- Dermatitis herpetiformis
Dermatitis herpetiformis is an intensely pruritic, symmetric, grouped vesicular and papular eruption on extensor surfaces that is a cutaneous manifestation of gluten-sensitive enteropathy (celiac disease). Diagnosis rests on skin biopsy with direct immunofluorescence plus celiac serology, and treatment combines a strict lifelong gluten-free diet with dapsone (starting 50 mg PO once daily, titrated within 50 to 300 mg daily) for rapid control of the itch while the diet takes effect.
- Lactose intolerance
Lactose intolerance is osmotic diarrhea, bloating, and flatulence caused by deficiency of the brush-border enzyme lactase, most often the primary age-related decline seen in people of Asian, African, or Native American descent. Diagnosis rests on symptom resolution with lactose elimination and recurrence on rechallenge, confirmed when needed by a hydrogen breath test, and treatment is dietary lactose restriction with lactase enzyme replacement and calcium and vitamin D intake.
- Small intestinal bacterial overgrowth
Small intestinal bacterial overgrowth is excessive bacterial colonization of the proximal small bowel, driven by stasis from strictures, blind loops, or dysmotility, or by loss of gastric-acid and immune defenses, producing bloating, diarrhea, and fat and B12 malabsorption. Diagnosis rests on a carbohydrate breath test or jejunal aspirate culture, and treatment corrects the underlying cause while a course of rifaximin or another antibiotic reduces the bacterial burden.
- Microscopic colitis
Microscopic colitis is a cause of chronic watery, non-bloody diarrhea in older women with a grossly normal colonoscopy, diagnosed only by random colon biopsy showing lymphocytic or collagenous histology. Management starts with stopping culprit drugs and antidiarrheals, then oral budesonide for induction and, if needed, maintenance.
- Osteoporosis
Osteoporosis is low bone strength that raises fragility fracture risk, diagnosed by a hip or spine T-score of -2.5 or less or by a fragility fracture itself. First-line treatment is an oral bisphosphonate, alendronate or risedronate, alongside adequate calcium and vitamin D intake.
- Crohn disease
Crohn disease is a chronic transmural inflammatory bowel disease that can affect any segment from mouth to anus in skip lesions, most classically the terminal ileum, and is confirmed by ileocolonoscopy showing cobblestoning, skip areas, and non-caseating granulomas on biopsy. Management follows an ordered sequence of glucocorticoid or budesonide induction followed by immunomodulator or biologic maintenance, with surgery reserved for fixed complications rather than cure.