Paradoxical development of Kimura's disease in a patient treated with mepolizumab for bronchial asthma

A male patient in his early 30s was diagnosed with bronchial asthma 3 years previously. He responded well to inhaled corticosteroids and long-acting beta-agonists. Approximately 18 months from the onset, the patient reported worsening symptoms. These symptoms included severe functional limitations, requiring frequent exposure to high-dose prednisolone. Mepolizumab was added to the treatment, leading to optimal control of bronchial asthma. Despite receiving seven doses of mepolizumab at monthly intervals, the patient developed cervical and postauricular lymphadenopathy and subcutaneous swelling of soft tissue. A cervical lymph node biopsy confirmed the diagnosis of Kimura disease. Following treatment with oral glucocorticoids and methotrexate, the patient experienced a complete resolution of symptoms. He has been in remission and off oral prednisolone for the last 13 months. In this case, we highlight the development of Kimura disease in a patient undergoing mepolizumab treatment.