Granulomatous Oral Lesion in a Patient with Crohn’s Disease: A case report

The human body is a complex system where different parts often communicate, sometimes in ways that are difficult to predict. One such connection exists between the gut and the mouth, linked by a chronic condition called Crohn's disease. This illness causes deep inflammation in the digestive tract, but it can also create painful sores and swelling inside the mouth. Because these mouth sores are caused by the body's immune system attacking its own tissues, they look very similar to sores caused by certain infections, particularly tuberculosis. Tuberculosis is a bacterial infection that usually affects the lungs but can spread to other parts of the body, including the mouth. In regions where tuberculosis is common, doctors face a difficult choice when a patient with Crohn's disease develops a mouth sore: is it just another flare-up of the gut disease, or is it a dangerous infection that requires completely different treatment? This distinction is critical because the medicines used to calm Crohn's disease work by weakening the immune system, which could make an active tuberculosis infection much worse if not treated first.

A team of researchers at Tunis El Manar University recently shared the story of a woman who faced exactly this diagnostic puzzle. The patient was a 51-year-old woman from North Africa who had been living with a severe form of Crohn's disease for 24 years. Her condition had affected her intestines and caused fistulas, which are abnormal tunnels that can form between organs. For several years, she had been treated with a combination of two powerful medications, infliximab and azathioprine, which suppress the immune system to keep her gut disease under control. In 2021, she began to experience a new problem: a chronic, painful sore on her tongue. The sore was not just a simple cut; it had raised edges, bled when touched, and was accompanied by a swelling of the tongue that made it feel heavy and uncomfortable. She also suffered from a persistent cough that had been bothering her for some time.

When doctors examined her, they found she was underweight and pale, with low levels of red blood cells and immune cells in her blood. A small sample of tissue taken from her tongue showed a specific type of inflammation called granulomatous inflammation. In simple terms, this means her body had formed tiny clusters of immune cells trying to fight something, but the test did not immediately reveal what that something was. Because this pattern of inflammation is seen in both Crohn's disease and tuberculosis, the medical team had to look closer. The patient's history of a chronic cough raised a red flag for tuberculosis, a disease that is still common in her region. To investigate, they took chest X-rays and a detailed CT scan of her chest. These images showed signs consistent with pulmonary tuberculosis, an infection in the lungs.

The path to a clear answer required careful steps. The doctors first tried to find the bacteria in her sputum, the mucus coughed up from the lungs, but the test came back negative. This is a common occurrence, as the bacteria can be hard to catch in a simple sample. Undeterred, the medical team performed a bronchoscopy, a procedure where a thin tube with a camera is passed down into the lungs to collect a deeper sample. This time, the test confirmed the presence of the tuberculosis bacteria. The diagnosis was now clear: the woman had active tuberculosis coexisting with her Crohn's disease. While her Crohn's disease was known to cause granulomatous oral involvement, the presence of the infection meant the oral lesion could not be attributed solely to Crohn's without ruling out tuberculosis, as the two conditions can mimic each other or occur together.

Once the true cause was identified, the treatment plan changed immediately. The doctors started her on a specific course of medication designed to fight tuberculosis. The results were swift and positive. As the infection began to clear, both the cough and the painful sore on her tongue started to heal. The swelling in her tongue went down, and the ulceration disappeared. This outcome confirmed that the initial suspicion of tuberculosis was correct and that treating the infection was essential to resolve her symptoms.

This case serves as a vital reminder for medical professionals, especially in areas where tuberculosis is common. It shows that when a patient with Crohn's disease develops a new mouth sore, doctors cannot simply assume it is part of the gut disease. The similarity in how these conditions look under a microscope can lead to a wrong diagnosis if the patient is not thoroughly checked for infection. The researchers emphasize that before attributing such lesions to Crohn's disease, it is essential to rule out tuberculosis, particularly in patients who are taking medicines that weaken their immune defenses. By catching the infection early and treating it directly, the patient was able to recover fully, avoiding the potential harm that could have come from continuing to treat her for the wrong condition. The story underscores the importance of looking beyond the most obvious explanation when the body presents a complex set of symptoms.