Pyoderma gangrenosum in a patient with multiple sclerosis under natalizumab treatment: a case report

Pyoderma Gangrenosum (PG) is often considered an immune-mediated disease. Up to 50% of PG cases - a rare, non-infectious inflammatory skin disease characterized by painful necrotic ulcers -are associated with underlying systemic diseases like Rheumatoid Arthritis (RA), and Inflammatory Bowel Disease (IBD), moreover with monoclonal antibody therapy.

We described a 38-year-old female patient with multiple sclerosis (MS) who was treated for three years with Natalizumab. Myalgia, fever, and erythematous plaques accompanied by painful lesions in both upper extremities manifested with the fifteenth dosage of NTZ. After comprehensive testing and a Magnetic Resonance Imaging (MRI) scan, we excluded other systemic diseases and a recurrence of multiple sclerosis, respectively. After consulting a dermatologist, a skin biopsy was performed, and pathology report confirmed PG. Eventually, the lesions began to heal after stopping NTZ injection without receiving any dermatological care.

Based on PG incidence, it was associated with some medications like Rituximab and Ocrelizumab, on the other hand, after discontinuation of NTZ the lesions started to heal even without dermatological treatment. In our situation, it is conceivable that NTZ injection, and PG incidence are connected.