Tuberculous Lymphadenitis in a Patient Treated with Dupilumab: A Case Report.

Tuberculous lymphadenitis is among the most frequent presentations of extrapulmonary tuberculosis; the most common presentation is isolated chronic non-tender lymphadenopathy in young adults without systemic symptoms. Dupilumab is a fully human monoclonal antibody directed against interleukin-4 receptor-α that blocks the synergistic effects of interleukin-4 and interleukin-13 on allergic inflammation. Its well-known adverse events are allergic conjunctivitis, injection site reaction, and dupilumab facial redness. A 32-year-old female with severe atopic dermatitis was treated with dupilumab for 2 months at our clinic. She complained of multiple enlarged palpable lymph nodes on the right side of the neck and inguinal area for 2 months. Laboratory tests showed an increased total eosinophil count and immunoglobulin E level, as well as positive interferon-γ release assays. Radiological examination showed multiple low echoic and heterogeneous well-enhancing lymph nodes in level II, III, IV, and V of the neck. Histological examination revealed caseous necrosis and tuberculoid granuloma. The lymph node enlargements were completely relieved after antituberculosis treatment. The mechanism for the development of tuberculous lymphadenitis in a patient receiving dupilumab is not fully understood yet. In some previous studies, treatment with dupilumab suppressed the expression of genes related not only to T helper 2 and eosinophil response but also to proinflammatory responses. It could not inhibit the intracellular growth of Mycobacterium tuberculosis in macrophages, predisposing them to the development of tuberculous infection. To the best of our knowledge, this is the first report on the development of tuberculosis lymphadenitis in a patient treated with dupilumab.