Viral STIs + skin lesions

Question 1

How does herpes present (primary and recurrent)?

Answer 1

PRIMARY (most severe)
-Flu-like illness
-Vulvitis
-Painful vesicles on the vulva
-Urinary retention due to pain on passing urine
RECURRENT
-Often asymptomatic
-Triggered by stress, sex, menstruation

Question 2

How is herpes diagnosed?

Answer 2

-Viral PCR of vesicle fluid ie skin swabs

Question 3

How is herpes managed?

Answer 3

-Aciclovir 400mg TDS - reduces severity and duration of flare
-Saline baths, emla cream, lignocaine gel

Question 4

What implications does herpes have for pregnancy?

Answer 4

-Risk of transmission to baby is low unless 1st infection in last stages of pregnancy (consider C section)
-Consider acyclovir if recurrent infections throughout pregnancy

Question 5

Which HPV types cause genital warts?

Answer 5

-Types 6 + 11

Question 6

How do genital warts present?

Answer 6

-Most infections of HPV are asymptomatic
-Can cause local skin irritation / catch on clothing
-Small, fleshy painless lump, spread in lines of trauma

Question 7

How are genital warts diagnosed?

Answer 7

-Mostly clinical
-May be found on cervical cytology from smear
-May require biopsy to exclude neoplasia

Question 8

How are genital warts managed?

Answer 8

-Podophyllotoxin topical treatment BD 3 days on 4 days off for 6 weeks
-Imiquimod 2nd line
-Cryotherapy, excision

Question 9

Where do molluscum contagiosum lesions appear?

Answer 9

-Genitals, pubic region
-Lower abdomen, upper thighs
-Buttocks
-Clear on their own

Question 10

How does the primary phase of syphilis infection present?

Answer 10

-Painless genital ulcer (= CHANCRE) - red, raised, well demarcated with indurated edge
-Inguinal lymphadenopathy
-Usually 10-90 days post infection

Question 11

How does the secondary phase of syphilis infection present?

Answer 11

-Develops in 25% of those who leave primary untreated
-Painless warty genital lesions (= CONDYLOMATA LATA)
-Hepatitis
-Splenomegaly
-Glomerulonephritis
-Neuro conditions eg CN palsies, meningitis, optic neuropathy, psychiatric symptoms
-Rash on palms and soles
-Occurs within 2 years of infection (but usually 4-10 weeks)

Question 12

How does the tertiary phase of syphilis present?

Answer 12

-Neurosyphilis
-Cardiovascular effects
-Gummatous of skin and bones

Question 13

How is syphilis diagnosed?

Answer 13

-Bloods - VDRL carbon antigen test, RPR test for screening
-Swab from primary lesion for dark field microscopy + PCR

Question 14

How do you manage syphilis?

Answer 14

Abx for symptoms
-Benzylpenicillin IM for 3 weeks (single dose if primary, secondary or early tertiary)
Doxy
-Erythromycin

Question 15

What implications does syphilis have for pregnancy?

Answer 15

Increased risk of:
-Preterm delivery
-Stillbirth
-Congenital syphilis (saddle nose, deafness, keratitis)
-Wrinkling around mouth

Question 16

What receptor does HIV bind to in human cells and what does this result in?

Answer 16

-CD4 on helper T cells, monocytes, macrophages and neural cells

Question 17

What is viral load used to predict?

Answer 17

-Impact of virus on immunity ie progression to AIDS
-CD4 count declines as viral load increases

Question 18

What occurs if HIV is left untreated?

Answer 18

-All cell-mediated immunity is progressively damaged
-Leaving patient more susceptible to infection and malignancies

Question 19

What antigens are tested for when testing for HIV and when should this be done?

Answer 19

-p-24 antigen
–Detected after 3-4 weeks of infection then reduces to v low levels after 8 weeks
-HIV RNA
–Sensitive 1 week before seroconversion symptoms
-HIV antibody
–Takes 4-8 weeks to develop
-4th generation tests recommended (tests for both), 3rd gen just tests for antibody and done in 12-week window

Question 20

What are the stages of HIV infection?

Answer 20

1. HIV binding + integration
   –Takes 3-5 days after exposure
2. Seroconversion –> primary infection
   –Causes flu-like symptoms in 70% of patients
   –Transient, 2-12 weeks post exposure
3. Period of asymptomatic infection
   –Average 5-10 years
   –Some constitutional symptoms eg night sweats, diarrhoea
4. AIDS
   –Typically around 8 years after infection (if no treatment)
   –Death within 2 years if no treatment

Question 21

What is considered a low CD4 count?

Answer 21

<200
-<350 at diagnosis indicates poor prognosis

Question 22

What is the risk of vertical transmission for HIV?

Answer 22

-If viral load <50 - vaginal delivery is possible
-Prolonged labour is a risk factor for VT
-C-section recommended if >400
-Neonatal PEP for 4 weeks in viral load >50
-Able to breastfeed if counselled and viral load is low

Question 23

When can PEP be used?

Answer 23

-Consider for anyone having UPSI / condom failure with a high-risk contact in last 72h
-Taken for 28 days

Question 24

When should PrEP be used?

Answer 24

-Before, during and after sex
-For HIV negative people