Lecture 34 - Genital Lesions Flashcards
Syphilis?
T. pallidum, evasive of immune response, CMI important, vasculitis and fibrosis due to immune response
Syphilis early manifestations?
solid painless ulcerations, rash, ocular lesions, neuro signs
Diagnosis techniques of syphilis?
dark field microscopy or direct fluorescent antibody, then serology
Secondary Syphilis?
4-10 weeks after primary (can overlap), haematogenous spread -> rash: macular, papular or papulosquamous @ trunk, extremeties. palms and soles, mucus membrane lesions, alopecia
Late syphilis?
no long infectious, typically asymptomatic but sometimes: aortic disease, optic atrophy, pyramidal signs, cognitive change, gumma
Congenital syphilis?
infection as early as 9wk, no inflamm response until 18wk, 50% 3rd trimester abortion or perinatal death, changes appear 1-2mnths age, mostly undetected early
Syphilis tests
screening w EIA, then confirm with RPR and TPPA; pregnancy can trigger false positive
EIA test?
utilises anti-human IgG and IgM, 99%+ sensitivity and specificty but lower for primary syphilis
RPR?
non-specific test, detects antibodies against lipoidal antigen, positive 3-5 wk post exposure, highly specific in healthy people
TPPA?
T. pallidum agglutination assay, diagnosis of late and early, specific but false positives can happen due to presence of Ab against other treponemals
Causes of false positives?
VDRL/RPR - technical, acute biological (fever, pregnancy), chronic biological (chronic infection, autoimmune); TPHA - SLE, leprosy
Treatment?
penicillin (doxycycline for allergic, desensitise if pregnant too)
Herpes infection?
mucosa more vulnerable than skin, replicates in epidermis, travels via unmyelinated sensory nervves to sacral paraspinal ganglia,
Herpes transmission?
direct virion contact from blisters or ulcers @ oral or genital, most symptomatic infection from asymptomatic partner,
Herpes diagnosis and treatment?
swab vesicle or ulcer, PCR for HSV-1/2; aciclover
