Concurrent oral and genital herpes simplex virus infection leading to diagnosis of pemphigus vulgaris: A case report

A 39-year-old woman presented with a one-month history of painful oral ulcers involving the inner lip, buccal mucosa, and pharynx, followed by fever and the appearance of multiple tender purulent genital ulcers. Tzanck smear from both oral and genital ulcers was positive for multinucleated giant cells, and HSV serology showed IgG positivity for HSV-1 and HSV-2. She was treated with oral aciclovir and co-amoxiclav, resulting in complete resolution of genital ulcers and partial improvement of oral lesions. Two weeks later, she developed new erosive skin and lip lesions. This case highlights the diagnostic challenge of differentiating herpes simplex virus (HSV) infection from early pemphigus vulgaris, as HSV may either trigger or mimic pemphigus lesions, underscoring the need for histological evaluation in atypical or persistent mucocutaneous ulcers. In this patient, the dermatology referral for skin biopsy, histologically confirmed the diagnosis of pemphigus vulgaris.