Methotrexate Induced Lymphadenitis: A Case Report

INTRODUCTION: Methotrexate-induced lymphadenitis (MILA), a rare adverse effect of methotrexate treatment, occurs in a small percentage of patients using the drug for autoimmune diseases like rheumatoid arthritis and psoriasis. The prevalence of MILA varies, with some studies suggesting higher incidence in rheumatoid arthritis cases. The exact mechanisms are not fully understood but involve direct toxic effects on lymphoid tissue and methotrexate's immunomodulatory actions. MILA may occur early or after prolonged use, presenting as localized or generalized lymph node enlargement. Here, we are presenting a case where the patient developed lymphadenitis following methotrexate therapy for rheumatoid arthritis. CASE REPORT: In this case, a 39-year-old woman with a history of Rheumatoid Arthritis, undergoing methotrexate treatment presented with complaint of swelling in the neck, joint pain, and local rise of temperature. She was admitted for further investigation. Routine tests were normal, but Fine Needle Aspiration Cytology (FNAC) revealed reactive lymphadenitis. Methotrexate was stopped on admission. The patient was kept under observation. Hydroxychloroquine along with other medications were continued. Remarkably, neck swelling regressed within 36 hours. The patient was discharged next day without any further complications. Causality assessment showed a possible relation between methotrexate and lymphadenitis. CONCLUSION: The association between lymphadenitis and methotrexate is complicated and requires further evaluation. This patient presented with a small swelling in the cervical region which regressed completely on withholding the medication. Such complications can be avoided with routine follow up if a definitive association can be established between the two. Further studies are required in this regard.