Man with a lesion in his mouth

53y, AA man, with PMH of GERD, Insomnia, Erectile dysfunction and primary syphilis (diagnosed and treated at least 25 years ago), presents to the office frustrated by recurrent painful mouth sores, which are not preceded by blisters. For the past several years, he has been told to have recurrent herpes labialis and is being treated with Valacyclovir suppressive treatment.
On exam, he has few round sub-centimeter superficial ulcers on an erythematous base scattered on the palate and upper lip.
Which of the following statements about this pathology is false?

1. The pathogenesis of these lesions is not clearly identified, although it could be predisposed by stress, immune dysfunction or toothpaste detergent.
2. It would not be inappropriate to culture the base of the ulcer and send for Tzanck smear and culture.
3. Given the history of syphilis in the past, a diagnosis of oral syphilis can be made based on the history and exam- CORRECT ANSWER
4. Although Amlexaonox is slightly more expensive than Triamcinolone in Orabase, it is considered to be more effective and should be used as first-line agent.
5. The diagnosis of HSV appears dubious and Valacyclovir should be discontinued.