[Development of cervical tuberculous lymphadenitis in a patient with Crohn's disease receiving infliximab despite of chemoprophylaxis with isoniazid].

We herein report a case of a 41-year-old female with a 14-year history of Crohn's disease who had been treated with diet and mesalazine. Because of inadequate control, therapy with infliximab was planned. She had a positive result on the interferon-gamma release assay (QuantiFERON TB). After active tuberculosis was ruled out by chest x-ray and computed tomography, she was started on a six-month course of isoniazid 7 weeks prior to starting infliximab. After 10 doses of infliximab (15 months of therapy), she presented with pain of cervical lymphadenopathy. A biopsy of the lymph nodes revealed Langhans giant cells from granulomas and a positive result of polylmerase chain reaction for Mycobacterium tuberculosis. The treatment with infliximab was discontinued and anti-tuberculosis therapy was started. Although treatment for latent tuberculosis infection lowers the risk of reactivation of tuberculosis due to tumor necrosis factor alpha-blockers, it cannot completely inactivate tuberculosis. Despite the completion of chemoprophylaxis, patients receiving such agents should be instructed to watch out for any symptoms associated with pulmonary and extrapulmonary tuberculosis such as fever, cough, malaise, body weight loss, night sweating and lymphadenopathy, and they should also be closely followed up.