When celiac disease is suspected, a healthcare provider will use several means of coming to a diagnosis:
- Medical history review
- Family health history review
- Blood testing
- Physical examination
- Intestinal biopsy
- Skin Biopsy
- Genetic Testing
Medical History and Family Health History Review
By reviewing personal medical history and family health history, a healthcare provider can possibly find indications of gluten intolerance. The physician will likely ask whether anyone in the patient’s family was diagnosed with celiac disease.
A patient suspected of having celiac disease will have their blood drawn for analysis by a lab. These tests can reveal antibodies commonly associated with the gluten intolerance illness.
If these blood tests do not show these antibodies are present, further blood analysis may be ordered which can provide even more detailed results. Before having blood drawn for these diagnostic tests, it is important that patients suspected of having celiac disease continue eating gluten-containing foods. This is because the blood test results indicate the body’s negative reaction to gluten. If no gluten has been recently consumed, false blood analysis may result.
As part of a physical exam, the doctor will look for signs of celiac disease. He or she will do this by checking the body for malnutrition or a rash, both signs of gluten intolerance.
The doctor will listen to abdominal sounds with a stethoscope, also tapping on the patient’s abdomen to check for any pain or bloating.
When blood tests come back as positive for indicators of celiac disease, a small intestine biopsy may be ordered. This biopsy can confirm the diagnosis. As part of a biopsy, a piece of tissue will be taken from the intestines for exam under a microscope. This test will be performed in a hospital or outpatient center. The patient will receive a local anesthetic and light sedation to make the process easier and pain free.
In some cases, general anesthesia may be used. When the patient is sedated, the doctor or technician uses an endoscope, a small camera with a light, to remove tiny samples of tissue from the small intestines. The endoscope reaches the small intestines through the patient’s mouth, down the esophagus, through the stomach and into the duodenum. While this is being done, the camera provides imagery to a monitor. This allows doctors to check the condition of the intestinal lining, while small tools emerge from the endoscope to collect the samples. After samples are collected, they are provided to a pathologist. Pathologists specialize in examining sampled tissues in a lab to make diagnoses. If the intestinal villi in the samples show damage, this may be a sign of celiac disease.
Dermatitis herpetiformis is the skin rash which often occurs along with celiac disease. A skin biopsy will remove small bits of skin tissue for examination under a microscope to assess the type of rash, when one is present. This biopsy will occur in a hospital or outpatient center, usually using local anesthesia. Some patients will be provided general anesthesia. If antibodies are present in the skin tissue when reviewed by a pathologist, the doctor may perform blood tests to confirm a celiac disease diagnosis.
Genetic blood tests can often indicate whether gene pairs containing human leukocyte antigen gene variants are present. Most people who have celiac disease have these gene variants. However, having them does not necessarily make a diagnosis definite. These anomalies just add to evidence that celiac disease is a possibility. Without the genes, celiac disease is unlikely the cause of symptoms.