22 - STIs 2 Flashcards
What is the pathophysiology and causative organism for genital herpes?
- Usually HSV-2 but can be HSV-1 if oral sex with cold sore, common in UK
- Direct contact with mucous membranes or viral shedding in mucous secretions (asymptomatic)
- HSV enters dormant latent phase in sacral nerve root ganglia that often reactivates when immunocompromised
How may genital herpes present?
Initial infection usually occurs within 2 weeks and most severe, Lasts for around 3 weeks
- Ulcers or blistering lesions
- Neuropathic pain (tingling, burning, shooting)
- Flu-like symptoms
- Dysuria
- Inguinal lymphadenopathy
What are some complications with a genital herpes infection?
Usually in those who are immunocompromised e.g HIV co-infection
- Superinfection: with bacteria or fungi
- Autonomic neuropathy: can cause urinary retention
- Autoinoculation: lesions can be passed to other areas of skin
- Central nervous system: aseptic meningitis and encephalitis
- Other: hepatitis, oesophagitis and keratitis among others
How is genital herpes diagnosed?
- Usually clinically
- Swab for NAAT to do PCR
- STI testing
Ask about sexual contacts including those with cold sores to try to find source of transmission
How is genital herpes treated?
- Aciclovir 400 mg three times a day for 5 days if in first 5 days of onset
- Saline bathing
- Topical lidocaine analgesia
- Avoid intercourse when symptomatic
- Advice to use condoms and disclose to all future partners
How is genital herpes treated?
- Aciclovir 400 mg three times a day for 5 days if in first 5 days of onset
- Saline bathing
- Topical lidocaine analgesia
What is the issue with genital herpes in pregnancy?
Risk of neonatal herpes simplex virus infection
If mother has already had primary infection before pregnancy she will have antibodies that will cross placenta and protect baby during delivery
Issue if primary infection during pregnancy
How is genital herpes managed in pregnancy?
Primary infection before 28 weeks: Treat with aciclovir then prophylactic aciclovir from 36 weeks. If asymptomatic can have normally delivery if infection was over 6 weeks ago. If symptoms then C-Section
Primary infection after 28 weeks: Treat with aciclovir then immediately give regular prophylactic aciclovir. Do C-section
Recurrent infection: Regular prophylactic aciclovir from 36 weeks. Can have normal delivery regardless of if active lesions or not
What is the causative organism for syphilis and what is the incubation period?
Treponema Pallidum
Spirchote bacteria
Usually 21 days between infection and symptoms (3-90 days)
What are the different stages of syphilis?
Primary: painless ulcer (chancre) at original site of infection e.g genitals. Resolves in 3-12 weeks
Secondary: Systemic symptoms 4-12 weeks after chancre
Latent Stage: patient becomes asymptomatic but has serological evidence of infection. Early latent for two years then late latent after two years
Tertiary: Rare, developed 15-40 years after initial infection. Development of gummas, cardiovascular issues and neurological issues e.g aortic regurgitation, heart failure, neurosyphilis
What are the symptoms at each stage of syphilis?
Primary:
- Painless ulcer called chancre (resolves over 3-4 weeks)
- Local lymphadenopathy
Secondary:
- Maculopapular rash
- Condylomata lata
- Low-grade fever
- Lymphadenopathy
- Alopecia
- Oral lesions
Tertiary:
- Gummas
- Aortic aneurysm
- Neurosyphilis
How does neurosyphilis present?
Can occur in secondary or tertiary stage
- Paralysis
- Tabes Dorsalis (demyelination of posterior columns of spinal cord - abnormal proprioception, abnormal vibration, abnormal sensation, upgoing plantars, absent ankle jerks)
- Occular syphillis
- Argyll-Robertson Pupil (constricted pupil that accommodates but does not react to light)
- Altered behaviour
- Dementia
How does congenital syphills present?
Vertical transmission from mother
- Early: presenting < 2 years after birth. Rash, haemorrhagic rhinitis (‘bloody snuffles’), lymphadenopathy, skeletal changes and hepatosplenomegaly
- Late: presenting > 2 years after birth. Persistent inflammation predominantly affects bones and teeth leading to characteristic features
How is syphilis transmitted?
- Direct contact with infectious lesions: contact with the chancre or infectious lesions of secondary syphilis can transmit the organism e.g sex
- Vertical transmission: crosses placenta, screening when pregnant
- Sharing needles
How is syphilis diagnosed?
Serological Screening: Antibody blood test for T.Pallidum. RPR and VDRL are non-specific and can have false positives.
Confirm if positive antibodies: Samples from site of infection and do PCR and Dark field microscopy
Who should be tested for syphilis?
- Contact with a person who has primary syphilis
- HIV-infected individuals
- Sexually active MSM
- High-risk sexual behaviour: other STIs, exchange sex for drugs/money, unprotected sex
- Routinely as part of a sexual health screen
How is syphilis treated?
Single deep IM dose of Benzathine Benzylpenicillin
In late syphillis and neurosyphilis injections done for 3 weeks and with Prednisolone to prevent Jarisch-Herxheimer reaction causing harm
Avoid sex for 2 weeks!!!
What is Jarisch-Herxheimer reaction?
Acute febrile illness within first 24 hours of treatment for syphilis with fever, rash, headache, myalgia, chills and rigors. Warn people about this before treatment
Occurs in 10-35 % of patientsand is most common in early syphilis. Usually self resolves in 12-24 hours, give NSAIDs for symptomatic relief
Reaction can be life-threatening in patients with late tertiary cardiovascular or neurosyphilis, so give prednisolone 40-60 mg once daily for three days starting 24 hours before the initial dose of anti-treponemal antibiotics
What are the different serological tests for syphilis antibodies?
Diagnosis based on tests, history and examination
Non-Treponemal Tests
- VDRL
- RPR
- Can be falsely positive
- Used to test response to treatment
Treponemal Tests
- TPPA
- EIA
- Remain active for life in adequately treated patients.
- A positive EIA with a non reactive RPR and a non reactive TPPA is a most likely a false positive EIA result. If clinical history suggests a risk for syphilis the EIA should be repeated in 3-4 weeks. A positive EIA with a non reactive RPR and a positive TPPA is consistent with treated syphilis.
How may genital warts present?
- New growth or lump
- Irritation
- Bleeding
How are genital warts managed?
Advice
- Advise condoms to reduce transmission
- Advise to stop smoking as can affect treatment
- No contact tracing necessary
Treatment
- Topical: Podophyllotoxin, Imiquimod, TCA
- Surgical: Cryotherapy, Electrocautery, Excision
What is Granuloma Inguinale?
STI caused by Klebsiella Granulomatis
Causes beefy red genital ulcers
Found in tropical areas
What are some differentials for genital ulcers?
- Chancre
- Herpes
- Granuloma Inguinale
- LGV
- Chancroid
What is pedoculosis pubis?
Pubic Lice
Direct contact with skin or clothing causes transmission
How may pubic lice present?
- Itching
- Visible lice
- Small blue macule if prolonged manifestation
Can be in pubic hair, anal hair, axilla, eyebrows, eyelashes and chest hair
How are pubic lice treated?
- Topical Permethrin
- Nit comb
- Wash all clothes and bedding used in last 2-3 days over 60 degrees
- Contact trace past 3 months
- STI screen
- If in child consider sexual abuse
Can give oral ivermectin 2 doses 7 days apart if really severe
What is Chancroid?
STI caused by Haemophilus Ducreyi
Multiple deep painful ulcers
Usually seen in Africa and Caribbean
How does Chancroid present?
Increases risk of HIV transmission as skin barrier broken down
What are some examples of penile skin conditions?
- Pearly penile papules
- Angiokeratomas
- Eczema
- Psoriasis
- SCC
- Lichen sclerosus
- Erythroplasia of Queyrat: squamous cell carcinoma in situ
