LGV Flashcards
Which C trachomatis serovar is the most common strain implicated in LGV infection?
L2
What proportion of MSM are more likely to be HIV positive and have LGV compared with non-LGV chlamydia?
8.2 times more
What are the 3 stages of LGV?
Primary lesion
Secondary lesion, lymphadenitis, lymphadenopathy or bubo
Tertiary stage OR Genito-anorectal syndrome
LGV can be classified into how many stages?
3
Primary LGV - incubation, symptoms/signs?
3-30 days
transient
painless papule, pustule, shallow ulcer or erosion
Where is genital ulceration due to LGV in women?
posterior vaginal wall
fourchette
vulva
cervix (occasional)
Where is genital ulceration due to LGV in men?
coronal sulcus
What is the typical presentation of LGV proctitis?
rectal pain anorectal bleeding mucoid and/or haemopurulent rectal dis- charge tenesmus constipation
C trachomatis serovars L1–L3 are lymphotropic, infecting lymphocytes and macrophages - describe the pathological process
thrombolymphangitis
perilymphangitis
regional dissemination characterised by inflammation and swelling of lymph nodes and surrounding tissue
What complication may arise from buboes in LGV?
ulceration and discharge pus from multiple points creating chronic fistulae
the ‘groove sign’ - what is it?
both inguinal and femoral lymph nodes enlarged they are noticeably separated by the inguinal ligament
How common is the ‘groove sign’ in LGV?
15-20%
What is the significance of the ‘groove sign’?
Pathognomonic of LGV
When does lymphadenopathy typically occur following primary LGV?
10-30 days
What is the pathological process in tertiary LGV?
persistence or progressive spread of C trachomatis
chronic inflammation and destruction of tissues
Proctitis
Proctocolitis mimicking Crohns
Fistulae
Strictures
Chronic granulomatous disfiguring fibrosis and scarring of the vulva
How likely is tertiary LGV?
vast majority of patients recover after the secondary stage
Current LGV outbreak - complications are rare
What is the potential long term sequelae of LGV?
genital lymphedema
persistent suppuration and pyoderma
association with rectal cancer
What additional STIs should be considered if LGV is suspected?
check for co-existing STIs particularly
herpes, gonorrhoea, syphilis
What level of PMNLs on rectal swab is predictive of LGV proctitis?
> 10 PMNLs per high-power field
Which sites can be used for sample collection for LGV?
ulcer base exudate
rectal mucosa
aspiration of lymph node or bubo
swab or FVU for urethral sample
What diagnostic techniques can be considered in LGV?
detection of DNA/RNA by NAAT
culture on cyclohgeximide-treated McCoy cells
Chlamydia serology
What are the limitations of LGV culture?
lower sensitivity than NAAT
labour-intensive
expensive
restricted availability
LGV lymphadenopathy - histology?
follicular hyperpla- sia and abscesses
non-specific but LGV should be on differential
How do we identify LGV-associated serovars of C trachomatis?
Restriction fragment length polymorphism (RFLP) analysis sequencing
