Reactivation of bullous pemphigus after stopping fingolimod in a patient with multiple sclerosis A case report from the island region.

Abstract

Introduction: Bullous pemphigus is an autoimmune disease characterized by subepidermal blisters and is associated with chronic neurological disorders such as multiple sclerosis (MS), linked to molecular mimicry phenomena. Standard treatment includes systemic corticosteroids.

Case Presentation: We report the case of a 62-year-old woman from Isabela Island (Galapagos) with a long-standing history of multiple sclerosis and biopsy-confirmed bullous pemphigus. The patient was admitted due to a progressive outbreak of lesions (tense, painful, and itchy blisters) after voluntarily discontinuing treatment with fingolimod a few weeks earlier. Additionally, the patient had irregular and near cessation of corticosteroid use.

Clinical Findings and Diagnosis: Upon admission, pemphigus bullous was diagnosed in the active stage, associated with an uncomplicated urinary tract infection and oral candidiasis. Skin biopsy showed the characteristic subepidermal blister formation. The unsupervised discontinuation of fingolimod, combined with inconsistent corticosteroid use, was believed to have contributed to immune rebound and facilitated blister reactivation.

Therapeutic Management and Outcome: Treatment was initiated with ceftriaxone, mid-dose oral prednisone, and a topical antifungal, along with general hygiene measures. The clinical course was favorable, with rapid improvement in pruritus, resolution of infection, and new epidermal formation. At discharge, the patient was clinically stable, and a telemedicine follow-up was arranged, enabling therapeutic adjustments and preventing unnecessary transfers from the island region.