A 28-year-old male presents with a generalized, non-pruritic maculopapular rash involving his palms and soles, which appeared about 6 weeks after an initial painless genital ulcer that resolved spontaneously. He also reports generalized lymphadenopathy and malaise. What is the most likely diagnosis?

Explanation

The patient's presentation is classic for secondary syphilis. The initial painless genital ulcer (chancre) is characteristic of primary syphilis, which typically resolves spontaneously. Weeks to months later, secondary syphilis manifests with a generalized, non-pruritic maculopapular rash, often involving the palms and soles, along with constitutional symptoms like malaise and generalized lymphadenopathy. Pityriasis rosea typically spares palms and soles and has a herald patch. Drug eruptions can be varied but the history of a preceding painless ulcer points away from it. Primary syphilis is characterized by the chancre itself, not the disseminated rash.