Which among the following is prognostic test for genital ulcer?

Ans: a (VDRL) Ref: Ananathanarayan, 7th ed, p. 382Among the following VDRL can be used to assess the prognosis because it is the only test that becomes negative after effective treatment of syphilis.VDRL- VDRL is a slide flocculation test- It detects IgG or IgM against cardiolipin antigen- It becomes positive after 7-10 days after the appearance of chancre or 3-5 weeks after the acquiring infection- Sensitivity in secondary syphilis is 100%- VDRL becomes negative 6-18 months after effective treatment of syphilisCauses of false positive VDRLAcute false positive reaction (< 6 months)Chronic false positive reaction (> 6 months)Recent viral infection or immunizationAgingAutoimmune disorderGenital herpesSLEHIV infectionRheumatoid arthritisMalariaParenteral drugParenteral drug use False negative VDRL -Prozone phenomenon (very high antibody titre)NoteMost sensitive test for syphilis -- FTA-ABSMost specific test -- TPITest of choice for rapid diagnosis -- RPRTest of choice for prognosis or evaluation of therapy -- VDRL