CHRONIC SPONTANEOUS URTICARIA DURING NATALIZUMAB THERAPY IN A PATIENT WITH MULTIPLE SCLEROSIS: A CASE REPORT

CASE PRESENTATION:

A 40-year-old female with a confirmed diagnosis of Multiple Sclerosis (MS) since 2016 was initially treated with Interferon beta-1a 44mg. In 2022, Natalizumab was initiated as part of her therapy regimen. In July 2023, she began to experience episodes of urticarial lesions accompanied by pruritus. By November 2023, she was diagnosed with chronic urticaria following the persistence of symptoms for more than 6 weeks. Differential diagnoses, including rheumatological conditions, were thoroughly investigated. Despite the administration of high-dose H1-antagonists and H2-antagonists as first and second-line treatments, there was no improvement. Subsequently, Omalizumab was introduced as a third-line therapeutic option.

DISCUSSION:

Chronic spontaneous urticaria (CSU) is characterized by the recurrent occurrence of pruritic wheals and/or angioedema lasting for over 6 weeks. Its etiology may involve autoantibodies or remain idiopathic, often devoid of identifiable external triggers. Previous literature has documented cases linking CSU with Relapsing Remitting Multiple Sclerosis, particularly in association with immunomodulatory agents such as interferons and alemtuzumab. Immunological dysregulation following medication administration appears to play a contributory role in this phenomenon. Standard therapeutic strategies involve the use of H1 and H2 antagonists, alongside leukotriene antagonists. In refractory cases, Omalizumab, an anti-IgE monoclonal antibody, has emerged as a safe and efficacious option.

FINAL COMMENTS:

Omalizumab demonstrates a favorable response rate of approximately 84% in cases of chronic urticaria. Its consideration in refractory chronic urticaria subsequent to the treatment of Multiple Sclerosis with immunomodulatory agents and monoclonal antibodies is warranted.