26th April 2024

A 28-year-old woman presents with painful vesicular lesions on her lips and oral mucosa, which appeared 3 days ago.

A 28-year-old woman presents with painful vesicular lesions on her lips and oral mucosa, which appeared 3 days ago. She reports a burning sensation prior to the appearance of the lesions. She has a history of similar episodes in the past, typically during periods of stress or illness. She denies any recent sexual activity or known exposure to genital herpes. Her medical history is unremarkable, and she is not currently taking any medications.

On examination, multiple small vesicles with surrounding erythema are noted on her lips and oral mucosa. There are no lesions elsewhere on her body, and no lymphadenopathy is detected.

Which of the following is the most likely diagnosis?