Syphilis
Pathogen: Treponema pallidum, spirochete (スパイラル状に長いバクテリア）
Diagnostics
Dx: 「Non-Treponemal test」と「Treponemal test」があって、definative testは、treponemal test。
Non-Treponemal test – Venereal Disease Research Laboratory (VDRL) test, rapid plasma reagin (RPR) – false(+) can be hepatitis, viral PNA, pregnancy, infectious mononucleosis.
Treponemal test – e.g.: fluorescent treponemal antibody absorption (FTA-ABS), Treponema pallidum particle agglutination (TP-PA), various enzyme immunoassays (EIAs)
The first test is a non-treponemal test which seems to be a simple blood test, but why not treponemal testing from the beginning if it is the definitive test?
Non-treponemal test does not take time and lower cost, but treponemal test takes longer and more expensive.
下の図によると、時期によっては、どちらのテストも陽性になる可能性があります。
そしてReference siteにある「Table1」の表によると、SensitivityとSpecificityにもそれほどの差がない(Satyaputra et al., 2021)ようです。
(Satyaputra et al., 2021)
Skin lesions
Primary stage: Chancres – painless ulcer
Secondary stage: maculopapular rash to trunk, neck, palm and soles. Secondary syphilis alopecia has patchy, moth-eaten, diffuse characteristics. Scalp and/or to the eyebrows (Tognetti et al., 2017). –> VDRL test Condylomata lata (コンジローマ）- wart-like lesions to moist areas (e.g., perineal area).
Tertialy stage (late-stage) – 10-20 years after the secondary stage – rubbery lumps or lesions to the SQ tissue.
Reference
Satyaputra, F., Hendry, S., Braddick, M., Sivabalan, P., & Norton, R. (2021). The Laboratory Diagnosis of Syphilis. Journal of clinical microbiology, 59(10), e0010021. https://doi.org/10.1128/JCM.00100-21. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8451404/
Tognetti, L., Cinotti, E., Perrot, J. L., Campoli, M., & Rubegni, P. (2017). Syphilitic alopecia: uncommon trichoscopic findings. Dermatology practical & conceptual, 7(3), 55–59. https://doi.org/10.5826/dpc.0703a12. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5661157/