GENITAL INFESTATIONS Flashcards
What is the most common viral sexually acquired infection?
Genital warts as a result of HPV
What does HPV stand for?
Human papilloma virus
How many HPV types have been discovered and how many infect the genital epithelium?
Over 100 types
40 of which infect genital epithelium
What are the two most common types of HPV virus to infect the genital epithelium and cause benign genital warts?
HPV 6
HPV 11
How are genital warts spread? What does this mean for sexual contact?
Direct skin to skin contact
This means that wearing a condom will not necessarily protect as condoms do not cover all the genital skin. It also means penetrative sex is not required for transmission.
What is the median incubation period for warts?
3 months (range of 2 weeks to 9 months or even longer)
What percentage of people with HPV genital infection will develop warts? Are they still infectious?
Many people (one estimate suggests 99%). However, they are still infectious, although those with genital warts are more likely to transmit HPV.
What are the clinical features of genital warts?
Lumps in the genital area (may be singular or multiple)
Usually asymptomatic
Can be itchy
Where do genital warts tend to occur?
In locations which undergo small trauma during sexual intercourse, but may be seen anywhere on genital skin:
Penile
Intrameatal
Peri-anal
Intra-anal
Vulva
Intra-vaginal
Cervical
What are the different types of genital wart based on appearance?
Condylomata acuminata
Smooth papules
Flat papules
Keratotic warts
What do condylomata acuminata genital warts look like?
Cauliflower-like appearance
Skin coloured, pink or sometimes hyperpigmented
If on mucosal surfaces then generally non-keratinised
If on skin then may be keratinised
What do smooth papular genital warts look like?
Smooth
Dome-shaped
Skin-coloured
What do flat papular genital warts look like?
Macular to slightly raised
Flesh coloured with smooth surface
More commonly found on internal structures (eg cervix), but do also occur on external genitalia
What do keratotic genital warts look like?
Thick horny layer
Resemble common warts or seborrheic keratosis
How is diagnosis of genital warts usually made?
Clinical diagnosis based on examination under bright light
What should prompt biopsy of a genital growth?
Unclear diagnosis
Pigmented lesions
Indurated lesions
Fixed lesions
Do not respond or worsen with treatment
Persistent ulceration or bleeding
Immunocompromised patients (where more vigilance is required to recognise pre-malignant lesions)
What is the differential diagnosis for genital growths?
Infections:
Molluscum contagiosum
Condylomata lata of syphilis
Acquired dermatological conditions: Seborrheic keratosis Lichen planus Fibro-epithelial polyp, adenoma Melanocytic naevus Neoplastic lesion
Normal variants: Pearly penile papules/coronal papillae Fordyce spots Vestibular papillae (micropapillomatosis labialis) Skin tags
What investigations should be done in someone with genital warts?
STI screen to exclude concurrent STIs
In someone diagnosed with genital warts, how do we go about contact tracing?
We don’t. However, current partners may benefit from assessment to exclude undetected STI.
How does a diagnosis of genital warts affect a woman’s cervical smear screening schedule?
It doesn’t
What percentage of genital warts will disappear without treatment by 3 months?
5-30%
What percentage of genital warts will stay the same by 3 months?
20%
What percentage of genital warts will get bigger by 3 months?
50%
Which group of patients are more likely to see spontaneous resolution of genital warts?
Children
What are the first line treatment options for non-keratinised larger vulval, perineal, penile or perianal warts?
Podophyllotoxin 0.5%
OR
Imiquimod
What are the first line treatment options for keratinised, small number or low volume vulval, perineal penile or penile warts
Cryotherapy
OR
Imiquimod
What class of medication is imiquimod?
Alpha-interferon stimulant
What are the second line treatments for more persistent warts?
Excision
Electrosurgery
Laser treatment
Within what time period are warts likely to respond to topical treatment?
2-3 months
How do we treat intra-vaginal warts?
Treatment often not necessary.
Cryotherapy
Electrosurgery
Trichloroacetic acid (TCA)
How do we treat cervical warts?
Treatment often not necessary
Cryotherapy
Electrosurgery
Laser ablation
Excision
Trichloroacetic acid (TCA)
Consider colposcopy if uncertain about diagnosis
How do we treat urethral meatal warts?
If base of lesion is seen:
Cryotherapy
Electrosurgery
Laser ablation
Podophyllotoxin 0.5% or imiquimod
If lesion is deeper is urethra:
Often no requirement needed
Surgical ablation under direct vision
How do we treat intra-anal warts?
Treatment often not necessary
Cryotherapy
Electrosurgery
Laser ablation
Trichloroacetic acid (TCA) - with care
Podophyllotoxin
Imiquimod
What percentage of patients will experience a recurrence of genital warts within 3 months of treatment?
30-60%
Within what time frame will most HPV infections clear in immunocompetent patients?
2 years
What percentage of patients are left with subclinical HPV?
10%
What are the main complications of genital warts?
Detriment to quality of life
Low self-esteem
Clinical depression
Increased stress
Negative impact on relationships
What is the organisms that causes molluscum contagiosum?
Pox virus
How is the pox virus transmitted to cause molluscum contagiosum?
Skin to skin contact - and therefore can be sexually transmitted but this is not the only way
What groups of patients is molluscum contagiosum most commonly found in? What sites are most commonly affected?
Children - hands, face, arms and trunk
What is the incubation period for molluscum contagiosum?
3-12 weeks (but can be up to 6 months)
What are the clinical features of genital molluscum contagiosum?
Papular lesions
1-3 mm in size
Smooth
Pearly coloured - resemble vesicles but in fact solid
Central umbilication
Affects skin around pubic hair, thighs, buttocks and lower abdomen
Normally spares mucous membranes
How do we diagnose molluscum contagiosum?
Normally clinically through inspection
If doubt, central punctum can be extracted and poxvirus-like particles viewed under electron microscope. Histology will also reveal enlarged epithelial cells with intracytoplasmic molluscum bodies.
What investigations should be done in someone who presents with genital molluscum contagiosum?
Full STI screen
When do we treat molluscum contagiosum?
It is only treated for cosmetic reason. It usually resolves spontaneously in 3 months
How do we treat genital molluscum contagiosum?
Cryotherapy
Extraction of central core
Piercing with stick that has been dipped in tincture of iodine or phenol
What percentage of patients will experience a recurrence of molluscum contagiosum within 8-24 months?
35%
What is the microorganism responsible for scabies?
Parasitic mite Sarcoptes scabiei
How is scabies transmitted?
Direct prolonged skin to skin contact
How long does skin to skin contact need to be maintained for in order to transmit scabies?
20 mins
What causes the symptoms of scabies?
Hypersensitivity reaction to absorbed mite excrement into skin capillaries
How long after first infection do symptoms of scabies usually take to come to fruition?
May take up to 4-6 weeks
How long after re-infection do symptoms of scabies take to come to fruition?
24-48 hours because of previous sensitisation.
What are the main symptoms of scabies?
Intense itching
Especially at night
Polymorphic and symmetrical rash
Burrowed appearance to rash - small raised greyish wavy channel on skin surface extending from an erythematous papule
Reddish-brown pruritic nodules - found especially on scrotum, penis and groin
Excoriations
What are the main sites affected by scabies?
Interdigital spaces of hands
Flexor surfaces of wrists
Extensor surfaces of elbows
Anterior axillary folds
Buttocks
Genitalia in males
Periumbilical region
How is scabies usually diagnosed?
Clinical diagnosis based on classic appearance
Confirmation by microscopic presence of mite, eggs or faecal excrement can be performed from skin scrapings, curettage or shave biopsy
What investigations would you do for someone with scabies?
Full STI screen
How do we treat scabies?
Avoid close contact until patient and partner have completed treatment
Topical permethrin 5% aqueous lotion
Topical malthion 5% aqueous lotion
Applied to whole body from neck downwards and then washed off 12 hours later (best to apply overnight)
Anti-histamines for itch
Bed linen and clothes should be washed at 50˚
What are the complications of scabies?
Itch may persist for several weeks following treatment
What is the form of scabies that occurs specifically in immunocompromised patients and the elderly?
Norwegian scabies
What are the clinical features of Norwegian scabies?
Widespread
Crusted lesions with thick scales
Only a mild itch
How do we treat Norwegian scabies?
Ivermectin
What are the more commonly used names for pediculosis pubis?
Crabs
Pubic lice
Which areas are affected by pubic lice?
Hairs of the:
Pubic and perianal areas
Thighs
Abdomen
Axillae
Eyebrows
Eyelashes
How are pubic lice transmitted?
Direct skin to skin contact
What is the incubation period of pubic lice?
Between 5 days and several weeks
What are the clinical features of crabs (or pubic lice)?
Itch
Rust coloured spots on underwear - represents louse faecal matter
How do we manage pubic lice?
Avoid close body contact and treat partner
Topical treatments:
Malthion 0.5% aqueous lotion - apply and leave for 12 hours
Permethin 1% cream - apply and leave for 10 minutes, can be used on eyelashes
Phenothrin 0.2% - apply and leave for 2 hours
Carbaryl 0.5% and 1% - apply and leave for 12 hours
Second application after 3-7 days required.
Fine tooth comb should be used to clear out dead eggs