Infectious Diseasesmiddle twist
A 31-year-old man who has sex with men presents with a two-week history of a non-itchy pinkish rash on his trunk that now involves his palms and soles, together with malaise and swollen glands in his neck, armpits and groin. Six weeks ago he noticed a painless firm sore on the shaft of his penis that healed on its own. He has no history of drug allergy. Serology: rapid plasma reagin 1:128, *Treponema pallidum* particle agglutination reactive. HIV antigen/antibody test is negative. He has no headache, visual or hearing symptoms.
Which one of the following is the most appropriate treatment?