A 20-year-old man presented five days after developing odynophagia, rhinorrhea, and cough. His cough and rhinorrhea had improved without intervention, but the odynophagia had worsened. He also had dysuria and painful lesions on his lips. The patient did not have a history of similar episodes. He had not used any medications recently, including over-the-counter medications, and did not have a history of allergies.

There were superficial white plaques on his tongue that could be scraped off and superficial erosions and ulcerations on his lips and buccal surface (Figure 1). Physical examination also revealed bilateral conjunctival injection (Figure 2). A small erosion was present on his urethra. There was no other skin involvement.

Question

Based on the patient's history and physical examination findings, which one of the following is the most likely diagnosis?

• A. Behçet syndrome.

• B. Erythema multiforme.

• C. Reactive infectious mucocutaneous eruption.

• D. Stevens-Johnson syndrome.