Ectoparasites Flashcards
The most common genital and pubic ectoparasite infestations are ______
Scabies and pubic lice (crabs)
Scabies transmission is through…
Skin-to-skin contact with someone with scabies
Occasionally acquired via bedding or furnishings
Pubic lice transmission is through…
Close contact
Pubic lice are less frequently seen in NZ since ________ has become common
Removal of pubic hair
Scabies is associated with what sort of housing conditions?
Crowded living or sleeping conditions
Institutional outbreaks have been reported
Are pubic lice only found in the genital area?
Pubic lice can sometimes be found on coarse hair elsewhere on the body, e.g. eyebrows, eyelashes, chest and axillae
Signs and symptoms of pubic lice/scabies
Pubic or genital itch (especially at night with scabies)
Rash
Scabies: genital papulonodules with or without generalised itch
Pubic lice: debris in underwear
Are complications of scabies common?
Uncommon and mostly occur in crusted scabies
What are the complications of scabies
Fever (children)
Pain on movement
Sleep disturbance
Secondary bacterial infection
Are complications of pubic lice common?
Uncommon
What are the complications of pubic lice
Fever, lethargy, irritability (more common in the young and frail)
Secondary bacterial infection
How long does scabies survive off the host?
Usually survive for less than 48-72 hours off host
How long do pubic lice survive off the host?
<24h
Treatment of scabies
Permethrin 5% cream or lotion
Apply to dry skin from scalp to soles of feet. Leave on skin for min 8hr.
Repeat in 1 week
When applying permethrin for treatment of scabies need to pay particular attention to…
Hands and genitalia
Apply under the nails with a nailbrush
How long do you leave permethrin on for treatment of scabies?
Minimum 8 hours
Usually overnight
Need to reapply to hands if washed
The time permethrin is left on the skin for treatment of scabies may be increased to ________ if there has been a treatment failure
24 hours
What else should people do as part of treatment of scabies?
On day of treatment environmental decontamination should be performed by hot washing bedding and clothing + when treatment repeated in 1 week
2nd line treatment scabies
Ivermectin as a single dose then repeated in 7 days
Needs SA + discussion with derm/ID/micro
Treatment of pubic lice
Permethrin 5% cream or lotion to all hairy parts of the body apart from the eyelids and scalp
Wash off after 10 minutes
When and in what situation should treatment for pubic lice be repeated?
Repeat treatment in 7-10 days if live lice are still found
2nd line treatment pubic lice
Ivermectin as a single dose (unapproved indication/not funded)
Repeat treatment in 7 days
Recommended action for complicated infection, e.g. crusted scabies
Consider HIV serology
Seek specialist advice for treatment (dermatology, ID or clinical microbiologist)
How long does the itch remain after treatment for scabies?
Common for itch to persist for a few weeks after treatment
Ongoing symptoms post treatment for scabies may be due to…
Lack of thorough treatment application
Lack of synchronising treatment with known close contacts leading to re-infection
Resistance to treatment
Development of irritant contact dermatitis due to topical scabicide
Is permethrin safe in pregnancy/breastfeeding?
Yes
What situations should you seek specialist advice for treatment (derm/ID/micro)
Complicated infection
Persistent infection (reinfection excluded)
Infection in infants
Allergy/contraindication to treatment
Treatment of pubic lice in eyelashes
Permethrin should not be applied near the eyes. Lice and nits can be removed by using a pair of fine forceps.
Alternatively, petroleum jelly can be smeared on the eyelashes twice daily for at least 3 weeks. This suffocates the lice and their nits
Is f/up or test of cure needed for scabies/pubic lice?
No
