What is celiac disease?
What is celiac disease?
Celiac disease (CD) is an immune mediated injury to the small intestine that is caused by ingestion of gluten (a name for multiple proteins in wheat, rye and barley) in genetically susceptible individuals. This can cause a variety of symptoms and result in poor absorption leading to deficiencies of nutrients including fat, protein, carbohydrates, vitamins and minerals such as iron and calcium.
Dermatitis herpetiformis (DH) is “celiac disease of the skin”. It is characterized by a blistering, intensely itchy skin rash. The rash is usually symmetrical and is found most frequently on the elbows, knees, buttocks and upper back. Patients with DH often have mild or no gastrointestinal symptoms, but villous atrophy is present in the majority of cases.
Pathogenesis
The pathogenesis of CD involves three factors: genetic, environmental and immunologic. Almost all individuals with celiac disease have the HLA-DQ2 and/or HLA-DQ8 genetic markers. Gluten is the trigger for the immunologic response of celiac disease. Pregnancy, surgery, gastrointestinal infection or severe emotional stress sometimes triggers the disease in genetically predisposed individuals. Celiac disease is an inherited condition and, therefore, first-degree and to a lesser extent second-degree relatives are at higher risk of developing the disorder.
Prevalence
Celiac disease affects about 1% of the population, making it one of the most common chronic gastrointestinal disorders.
Symptoms
Celiac disease can manifest at any age once foods containing wheat, barley, or rye are introduced in the diet. Symptoms of classical celiac disease include diarrhea, abdominal pain/distension and weight loss. Patients can be severely malnourished. Some patients present with non-intestinal symptoms (e.g., neurological issues), while others may have an associated condition with or without celiac-related symptoms. Iron or folate deficiency anemia can occur due to malabsorption. Children may present with short stature, delayed puberty, or dental enamel defects. Many symptoms (e.g., anemia, weight loss, bone pain, paresthesia, edema, skin changes) can be present. The number and severity of symptoms can vary greatly from person to person. In many cases, the disease is sub-clinical (silent) and is discovered only by blood screening. The presence of obesity does not exclude the diagnosis of CD.
Symptoms of CD may include one or more of the following:
Classical Symptoms
Associated Conditions
Celiac disease often occurs with other diseases. If you have any of the following conditions, consider having your blood tested for celiac disease:
Diagnosis
Studies from Canada and other countries report significant delays in the diagnosis of celiac disease. The similarity of the symptoms of CD with those of other diseases often leads to misdiagnoses such as irritable bowel syndrome, lactose intolerance and chronic fatigue syndrome, resulting in delayed diagnosis. Excellent serological blood tests are now available to screen for CD. The IgA tissue transglutaminase antibody (IgA-TTG) testing is recommended for initial screening. Since these tests are IgA based, they may be falsely negative in patients with selective IgA deficiency. The prevalence of IgA deficiency is higher in patients with CD; therefore, screening for selective IgA deficiency should be performed at the same time as the serological tests. In individuals with IgA deficiency, the laboratory may be able to perform IgG-TTG or IgG-deamidated gliadin peptide antibody (IgG-DGP).
Following a positive result on the blood test, the diagnosis of celiac disease should be confirmed with endoscopic small intestinal biopsy while consuming a regular GLUTEN containing diet. It is strongly recommended that the biopsy be done BEFORE starting a gluten-free diet in order to avoid a false negative biopsy result. The diagnosis of DH can be confirmed with a skin biopsy.
Over 99% of patients with celiac disease are positive for HLA-DQ2 or DQ8 genes. A negative HLA-DQ2 or DQ8 test is helpful to exclude the diagnosis of CD. However, approximately 30% of the general population has one of these HLA types, and most do not develop CD. Therefore, presence of these genes does not confirm CD.
Treatment
The treatment of celiac disease and dermatitis herpetiformisis a STRICT GLUTEN-FREE DIET FOR LIFE. Patients with DH may also require treatment with medications (e.g. dapsone). A gluten-free diet enables the intestine to recover with resolution of symptoms and can also reduce the risk of developing many of the complications of untreated CD.
Because of the complexity of the diet, patients should be referred to a qualified dietitian with expertise in gluten-free diet for nutrition assessment, education and follow-up. Regular annual follow-up with a physician is also recommended.
The safety of oats in CD has been extensively investigated. Clinical studies have shown that pure, uncontaminated oats are safe for nearly all adults and children. However, most commercially available oats are contaminated with wheat, rye or barley. Patients with CD must ensure that the oats they are eating are free from gluten contamination.
Detailed information on diagnosis and management of CD and DH is available for public and health care professionals at http://www.celiac.ca
Celiac disease (CD) is an immune mediated injury to the small intestine that is caused by ingestion of gluten (a name for multiple proteins in wheat, rye and barley) in genetically susceptible individuals. This can cause a variety of symptoms and result in poor absorption leading to deficiencies of nutrients including fat, protein, carbohydrates, vitamins and minerals such as iron and calcium.
Dermatitis herpetiformis (DH) is “celiac disease of the skin”. It is characterized by a blistering, intensely itchy skin rash. The rash is usually symmetrical and is found most frequently on the elbows, knees, buttocks and upper back. Patients with DH often have mild or no gastrointestinal symptoms, but villous atrophy is present in the majority of cases.
Pathogenesis
The pathogenesis of CD involves three factors: genetic, environmental and immunologic. Almost all individuals with celiac disease have the HLA-DQ2 and/or HLA-DQ8 genetic markers. Gluten is the trigger for the immunologic response of celiac disease. Pregnancy, surgery, gastrointestinal infection or severe emotional stress sometimes triggers the disease in genetically predisposed individuals. Celiac disease is an inherited condition and, therefore, first-degree and to a lesser extent second-degree relatives are at higher risk of developing the disorder.
Prevalence
Celiac disease affects about 1% of the population, making it one of the most common chronic gastrointestinal disorders.
Symptoms
Celiac disease can manifest at any age once foods containing wheat, barley, or rye are introduced in the diet. Symptoms of classical celiac disease include diarrhea, abdominal pain/distension and weight loss. Patients can be severely malnourished. Some patients present with non-intestinal symptoms (e.g., neurological issues), while others may have an associated condition with or without celiac-related symptoms. Iron or folate deficiency anemia can occur due to malabsorption. Children may present with short stature, delayed puberty, or dental enamel defects. Many symptoms (e.g., anemia, weight loss, bone pain, paresthesia, edema, skin changes) can be present. The number and severity of symptoms can vary greatly from person to person. In many cases, the disease is sub-clinical (silent) and is discovered only by blood screening. The presence of obesity does not exclude the diagnosis of CD.
Symptoms of CD may include one or more of the following:
Classical Symptoms
- Abdominal distension
- Abdominal pain
- Chronic diarrhea
- Loss of appetite
- Irritability
- Weight loss (or failure to thrive in children)
- Muscle wasting
- Dermatitis herpetiformis (DH)
- Relative of individual with CD (8-15%)
- Type 1 diabetes mellitus (4-8%)
- Autoimmune thyroiditis (2-5%)
- Trisomy-21 (Down syndrome) (2-5%)
- Turner syndrome (2-5%)
- IgA deficiency (2-5%, up to 30% in patients with gastrointestinal symptoms)
Associated Conditions
Celiac disease often occurs with other diseases. If you have any of the following conditions, consider having your blood tested for celiac disease:
- family history of celiac disease
- osteoporosis
- type 1 diabetes mellitus
- lymphoma
- autoimmune thyroid disease
- Down syndrome, Turner syndrome
- unexplained liver enzyme elevations
- autoimmune hepatitis
- unexplained infertility
- Unexplained iron or folate deficiency anemia
- Aphthous stomatitis (oral canker sores)
- Dental enamel defects
- Persistent/recurrent vomiting
- Irritable bowel syndrome
- Chronic constipation
- Elevated liver enzymes (ALT/AST)
- Arthritis, arthralgia
- Osteoporosis/Osteopenia
- Short stature
- Delayed puberty
- Infertility
- Unexplained ataxia
- Peripheral neuropathy
- Epilepsy with occipital calcifications
- Depression/anxiety
- Chronic fatigue
Diagnosis
Studies from Canada and other countries report significant delays in the diagnosis of celiac disease. The similarity of the symptoms of CD with those of other diseases often leads to misdiagnoses such as irritable bowel syndrome, lactose intolerance and chronic fatigue syndrome, resulting in delayed diagnosis. Excellent serological blood tests are now available to screen for CD. The IgA tissue transglutaminase antibody (IgA-TTG) testing is recommended for initial screening. Since these tests are IgA based, they may be falsely negative in patients with selective IgA deficiency. The prevalence of IgA deficiency is higher in patients with CD; therefore, screening for selective IgA deficiency should be performed at the same time as the serological tests. In individuals with IgA deficiency, the laboratory may be able to perform IgG-TTG or IgG-deamidated gliadin peptide antibody (IgG-DGP).
Following a positive result on the blood test, the diagnosis of celiac disease should be confirmed with endoscopic small intestinal biopsy while consuming a regular GLUTEN containing diet. It is strongly recommended that the biopsy be done BEFORE starting a gluten-free diet in order to avoid a false negative biopsy result. The diagnosis of DH can be confirmed with a skin biopsy.
Over 99% of patients with celiac disease are positive for HLA-DQ2 or DQ8 genes. A negative HLA-DQ2 or DQ8 test is helpful to exclude the diagnosis of CD. However, approximately 30% of the general population has one of these HLA types, and most do not develop CD. Therefore, presence of these genes does not confirm CD.
Treatment
The treatment of celiac disease and dermatitis herpetiformisis a STRICT GLUTEN-FREE DIET FOR LIFE. Patients with DH may also require treatment with medications (e.g. dapsone). A gluten-free diet enables the intestine to recover with resolution of symptoms and can also reduce the risk of developing many of the complications of untreated CD.
Because of the complexity of the diet, patients should be referred to a qualified dietitian with expertise in gluten-free diet for nutrition assessment, education and follow-up. Regular annual follow-up with a physician is also recommended.
The safety of oats in CD has been extensively investigated. Clinical studies have shown that pure, uncontaminated oats are safe for nearly all adults and children. However, most commercially available oats are contaminated with wheat, rye or barley. Patients with CD must ensure that the oats they are eating are free from gluten contamination.
Detailed information on diagnosis and management of CD and DH is available for public and health care professionals at http://www.celiac.ca
