Diagnosis and Treatment Challenges of an Atypical Case of Pemphigus vulgaris During the COVID-19 Pandemic.

Pemphigus defines a group of rare autoimmune blistering diseases that affect the skin and mucous membranes, with pemphigus vulgaris being the most common form that has increased morbidity and mortality in the absence of an early diagnosis and treatment. We report the case of a 24-year-old male with an atypical form of pemphigus vulgaris with cutaneous onset and subsequent involvement of the oral cavity. The management of the patient initially consisted of long-term systemic corticosteroid therapy. Following a mild form of SARS-CoV-2 infection and a flare-up of the disease in this context, which was not controlled with high doses of systemic corticosteroids, targeted therapy with rituximab was initiated but immediately stopped due to the manifestations of urticaria and angioedema. Considering the magnitude of these reactions, dapsone systemic therapy i.e., a steroid-sparing agent with minimal risk of infections, was started and managed to control the underlying disease. The management of this case of pemphigus vulgaris was challenging for both the patient and his physician, as the patient developed COVID-19 which caused disease complications and implied additional costs. This case highlights the importance of an accurate diagnosis given the atypical onset of the disease and the financial limitations with the impossibility of performing all confirmatory diagnostic tests.