Herpes Simplex Virus Type-1 Infection as a Trigger for Pemphigus Vulgaris.

Pemphigus vulgaris (PV) is a mucocutaneous autoimmune disorder that can be challenging to diagnose and treat. We discuss a clinical case of a patient with a previous medical history of autoimmune gastritis and vitiligo who presented with painful oral ulceration but was devoid of dermatological manifestations. Immunoglobulin M (IgM) antibodies and polymerase chain reaction (PCR) amplification of Herpes simplex virus type 1 (HSV-1) were detected from the base of the ulcers. Treatment with acyclovir only modestly improved the lesions. Anti-desmosome antibodies were positive, and an oral biopsy showed PV features. Treatment with prednisolone followed by rituximab (RTX) resulted in significant improvement.