Drug of Choice in primary syphilis is

PRIMARY SYPHILIS:-The primary chancre is a single, well circumscribed, painless ulcer with a clean floor and hard, indurated base on palpation. Hence it is called hard chancre.Occurs in genitals, perineal/perianal areas. Kissing ulcers can occur on the urethral meatus and coronal sulcus. An ulcer at the hilt of the shaft is called condom chancre. Extragenital sites include rectum, lips, oral mucosa, face, breasts etc.Treatment- benzylpenicillin injection 2.4 million units i.m 1 dose Or Inj. Procaine penicillin 12 lakh units i.m for 10 days. If allergic to penicillin- use doxycycline.{Reference: IADVL textbook of dermatology, vishalakshi Vishwanath pg no.126.}