Ectoparasites

Question 1

The most common genital and pubic ectoparasite infestations are ______

Answer 1

Scabies and pubic lice (crabs)

Question 2

Scabies transmission is through…

Answer 2

Skin-to-skin contact with someone with scabies
Occasionally acquired via bedding or furnishings

Question 3

Pubic lice transmission is through…

Answer 3

Close contact

Question 4

Pubic lice are less frequently seen in NZ since ________ has become common

Answer 4

Removal of pubic hair

Question 5

Scabies is associated with what sort of housing conditions?

Answer 5

Crowded living or sleeping conditions
Institutional outbreaks have been reported

Question 6

Are pubic lice only found in the genital area?

Answer 6

Pubic lice can sometimes be found on coarse hair elsewhere on the body, e.g. eyebrows, eyelashes, chest and axillae

Question 7

Signs and symptoms of pubic lice/scabies

Answer 7

Pubic or genital itch (especially at night with scabies)
Rash
Scabies: genital papulonodules with or without generalised itch
Pubic lice: debris in underwear

Question 8

Are complications of scabies common?

Answer 8

Uncommon and mostly occur in crusted scabies

Question 9

What are the complications of scabies

Answer 9

Fever (children)
Pain on movement
Sleep disturbance
Secondary bacterial infection

Question 10

Are complications of pubic lice common?

Answer 10

Uncommon

Question 11

What are the complications of pubic lice

Answer 11

Fever, lethargy, irritability (more common in the young and frail)
Secondary bacterial infection

Question 12

How long does scabies survive off the host?

Answer 12

Usually survive for less than 48-72 hours off host

Question 13

How long do pubic lice survive off the host?

Answer 13

<24h

Question 14

Treatment of scabies

Answer 14

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

Question 15

When applying permethrin for treatment of scabies need to pay particular attention to…

Answer 15

Hands and genitalia
Apply under the nails with a nailbrush

Question 16

How long do you leave permethrin on for treatment of scabies?

Answer 16

Minimum 8 hours
Usually overnight
Need to reapply to hands if washed

Question 17

The time permethrin is left on the skin for treatment of scabies may be increased to ________ if there has been a treatment failure

Answer 17

24 hours

Question 18

What else should people do as part of treatment of scabies?

Answer 18

On day of treatment environmental decontamination should be performed by hot washing bedding and clothing + when treatment repeated in 1 week

Question 19

2nd line treatment scabies

Answer 19

Ivermectin as a single dose then repeated in 7 days
Needs SA + discussion with derm/ID/micro

Question 20

Treatment of pubic lice

Answer 20

Permethrin 5% cream or lotion to all hairy parts of the body apart from the eyelids and scalp
Wash off after 10 minutes

Question 21

When and in what situation should treatment for pubic lice be repeated?

Answer 21

Repeat treatment in 7-10 days if live lice are still found

Question 22

2nd line treatment pubic lice

Answer 22

Ivermectin as a single dose (unapproved indication/not funded)

Repeat treatment in 7 days

Question 23

Recommended action for complicated infection, e.g. crusted scabies

Answer 23

Consider HIV serology

Seek specialist advice for treatment (dermatology, ID or clinical microbiologist)

Question 24

How long does the itch remain after treatment for scabies?

Answer 24

Common for itch to persist for a few weeks after treatment

Question 25

Ongoing symptoms post treatment for scabies may be due to…

Answer 25

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

Question 26

Is permethrin safe in pregnancy/breastfeeding?

Answer 26

Yes

Question 27

What situations should you seek specialist advice for treatment (derm/ID/micro)

Answer 27

Complicated infection
Persistent infection (reinfection excluded)
Infection in infants
Allergy/contraindication to treatment

Question 28

Treatment of pubic lice in eyelashes

Answer 28

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

Question 29

Is f/up or test of cure needed for scabies/pubic lice?

Answer 29

No