Primary syphilis

K Pavithran

 Department of Dermatology and Venereology, Malabar Institute of Medical Sciences, Calicut, India

Correspondence Address:
K Pavithran
Department of Dermatology and Venereology, Malabar Institute of Medical Sciences, Calicut
India

Syphilitic chancre presents usually as a single, painless, indurated clean-looking eroded papule or plaque on the glans penis or prepuce in males or in the cervix or labium majus in females. The inguinal lymph nodes are often enlarged, discrete, firm and non tender.

The laboratory diagnosis of syphilitic chancre depends on demonstration of Treponema pallidum by dark-field microscopy of serum taken from the ulcer. When chancre is in the cervix of uterus blood or serum is taken from the ulcer using a capillary tube, centrifuged and serum collected for DF microscopy. When chancre is secondarily infected or if the chancre is in the healing stage, specimen for DF microscopy is taken from the pulp of inguinal lymph node after injecting N. saline into it and withdrawing the tissue fluid with the same syringe.

Blood VDRL test and screening test for HIV are done in all cases of genital ulcers. VDRL test may be negative in the first 7 to 10 days of development of chancre (seronegative chancre). In such cases if DF also is negative I repeat the VDRL test after one week. I give significance even for a titre of 1:1 or 1:2, if the ulcer is clinically typical of primary chancre.

Once the diagnosis of primary syphilis is confirmed, I treat them with inj. benzathine penicillin 2.4, mega units (dissolved in 6 ml of distilled water) deep IM on upper outer quadrants (3m1 each) of each buttock. An intradermal test with aqueous benzyl penicillin is performed before injection of the therapeutic dose. All resuscitative measures to counteract anaphylaxis are kept ready before administering penicillin. They include 1. inj. adrenaline 1/1000 solution, 2: inj. hydrocortisone 3. oxygen 4. IV line.

Patient is advised of the possibility of developing Jarisch-Herxheimer reaction within the first 24 hours of treatment. For febrile Herxheimer reaction, only oral paracetamol is given.

Primary syphilis in a pregnant woman allergic to penicillin is treated with tab erythromycin stearate or base 500mg qid for 15 days. Newborns of these women are given treatment with IV penicillin as recommended for congenital syphilis even if there is no laboratory or clinical evidence of congenital syphilis in them.

I take special care for pregnant women treated for syphilis in second trimester, since treatment associated JH reaction may precipitate foetal distress or preterm labour. After delivery cord blood is taken for VDRL test to see whether there is passive reaginemia or true infection in the baby.

Primary syphilis in a patient with associated HIV infection is treated with penicillin regime as recommended for neurosyphilis ie inj. aqueous crystalline penicillin 2 to 4 million units IV every 4 hours for 10 to 14 days.

Sex partner of the patient is given treatment as recommended for early syphilis even if there is no clinical or laboratory evidence of syphilis in him/her (Epidemiological treatment).

All patients treated for primary syphilis are followed up clinically and serologically at 3 months intervals for 2 years. Patients treated with drugs other than penicillin and those who have associated HIV infection are followed up for a longer period.