A 42-year-old man presents to the dermatology clinic with a 2-week history of a spreading rash. He states that the rash began on his chest and abdomen and spread to his arms, legs, as well as his palms and soles. The rash is completely asymptomatic. He denies any recent illnesses or sick contacts, but he recalls an episode of a penile ulcer approximately 2 months ago, which resolved without any intervention. On examination, there is a generalized light pink papular rash on the back, chest and abdomen (63a). On the hands, there are red-brown macules scattered on the palmar aspects of the hands and fingers (63b).
i. What is the diagnosis and causative pathogen? What tests can be performed to confirm the diagnosis?
ii. What is the time course of the different stages of this infection? What are the cutaneous findings associated with each stage?
iii. What complication can be observed with treatment?
i. The patient presents with a history and clinical findings consistent with secondary syphilis, a sexually transmitted infection caused by the spirochete, Treponema pallidum.