Pediculosis and Scabies (3)

Question 1

What is pediculosis

Answer 1

lice infestation

Question 2

What are the 3 types of lice that feed on humans

Answer 2

Pediculus capitis (head lice)
Pediculus corporis (body lice)
Phthirus pubis (pubic lice)

Question 3

Head lice

Answer 3

Most common type of lice
Commonly picked up at schools and day care centers (increased risk with sharing of clothing, bedding, head pieces)
Can effect all socioeconomic groups

Nits (eggs) will be brown specks attached to hair
Live lice are white - note they are attached to hair, can’t easily shake off like dandruff

Question 4

Body lice

Answer 4

Live and lay eggs in seems of clothing

Can transmit infections (typhus and trench fever)

Occur in homeless people (not showering, changing clothing)

Question 5

Pubic lice

Answer 5

Mostly transmitted through sexual contact
Can also be through toilet seats, shared undergarments, bedding

Can also infest armpits, eyelashes, eyebrows, mustaches, and beards

aka crabs

Question 6

Life cycle of lice and why this is important to consider

Answer 6

Egg stage (nits)
-hatch in 8-9 days

Nymph stage
-grow of 9-12 days can’t lay eggs

Adult stage
-lay eggs

This is important to think about because some agents will only kill live lice, not eggs, so we may need to retreat when those hatch

Question 7

Lice goals of therapy and treatment approach

Answer 7

Get rid of lice by killing adult and nymph lice
Remove nits from hair (nit comb)

So first - apply pediculocide to infested body area for designated amount of time

Then - comb hair with nit comb to remove eggs and dead lice

Question 8

How is pediculosis diagnosed?

Answer 8

by visual inspection
if they do not allow you do to do a visual inspection you cannot recommend pediculicide

Question 9

What are some exclusions to self care for pediculosis

Answer 9

Hypersensitivity to chrysanthemums, ragweed, or other product ingredients

Presence of secondary skin infection (redness, oozing, puss - requires referral)

Eyelid or eyebrow involvement

Pregnancy/breastfeeding

Presence of active tumors

There are certain age restrictions for products

Question 10

What are the 2 OTC products used for lice

Answer 10

Pyrethrins + piperonyl butoxide = RID
-piperonyl butoxide is added to enhance pyrethrin concentration

Permethrin 1% = NIX

Question 11

What is RID vs NIX approved for

Answer 11

RID = head and pubic lice

NIX = head lice only

Question 12

RID administration/use

Answer 12

RID (pyrethrin) works by coming into contact with lice, blocking nerve transmission and therefore causing paralysis and death

So, contact time is important…
-apply to affected area for 10 minutes - then rinse and shampoo
-avoid eyes and mucus membranes
Then comb with nit comb

Since it does NOT kill eggs (only live lice), must be used again in 7-10 days to kill any nits that may have hatched

DO NOT apply more than twice in 24 hours (excessive contact time can increase absorption and lead to toxicity)

Question 13

RID ADRs

Answer 13

Irritation, erythema, itching, swelling

Question 14

RID should NOT be used in which patients? (2)

Answer 14

Those with chrysanthemum allergy
(caution with ragweed allergy)

And children under 2 years of age

Question 15

NIX administration/use

Answer 15

Apply to affected area for 10 minutes then rinse
-for head lice only
Then comb with nit comb

Retreatment is NOT required (unless active lice are detected)
-NIX does not kill eggs, but it has a lingering effect for up to 10 days - so that when eggs hatch they will be killed

Question 16

NIX adrs

Answer 16

Irritation, burning, itching, stinging
-minimal skin absorption

Question 17

NIX should not be used in which patients? (2)

Answer 17

Those with allergy to chrysanthemums or pyrethrin

Infants under 2 months

Question 18

What is the drug of choice for headlice?

Answer 18

Spinosad 0.9% topical suspension
(this is the drug of choice for head lice)
BUT it is RX only

Question 19

Spinosad place in therapy

Answer 19

only approved for HEAD lice
This is the drug of choice - but is limited by prescription only availability

can be effective for resistant lice that are not responsive to pyrethrin or permethrin

can be used in patients sensitive to chrysanthemums or pyrethrins

Question 20

Spinosad administration/use

Answer 20

Apply to dry scalp first, then apply to dry hair
Leave on for 10 minutes then rinse

Kills BOTH eggs and lice
-nit combing not required
-retreatment not required (unless active lice after 7 days of treatment)

Question 21

Spinosad can NOT be used in which patients?

Answer 21

Under 6 months old

Question 22

Which OTC lice therapy is superior after only ONE application

Answer 22

NIX … because it does not need to be applied again due to lingering effect for 10 days

But, in the case that it does need to be used twice - then RID and NIX are equally effective

Question 23

Scabies background/pathophysiology

Answer 23

“itch mite”
Parasites
Infection persists until they are removed (can live long on person, but only 48-72 hours off a host)

They get underneath the stratum corneum and deposit eggs - common in skin folds, under arms, in between fingers, buttocks, axillary folds, external male genitalia
But can also form in random spots

Question 24

How are scabies spread?

Answer 24

By direct, prolonged (20 minutes at least) skin to skin contact
-adult scabies is often sexually acquired

Can be spread indirectly through shared clothing, towels, or bedding - but not as common

Common in child care facilities
Nursing homes / long term care facilities
Prisons

Question 25

Scabies from dogs

Answer 25

Dogs CAN spread scabies - but these are different than human scabies
-the species that infects dogs, will NOT reproduce on humans

(specific scabies will only live in the specific species of host they are attracted to)

And dogs can NOT spread human scabies
So you can get scabies from a dog but it is self limiting

Question 26

Onset to symptom presentation with scabies

Answer 26

In scabies naive patients… may take 4-6 weeks to begin

In patients who have had scabies before… faster onset (typically 1-4 days after re-exposure) - makes sense - quicker reaction since they have been exposed to that irritant before

Question 27

Scabies symptom presentation

Answer 27

inflammation
intense itching
pimple like rash

Question 28

Can scabies be treated with OTC products?

Answer 28

NO - scabies is not a self care condition
need to see a provider for prescription therapy

Question 29

What 3 agents can be used for scabies treatment?

Answer 29

Permethrin 5% (note 1% was used for lice OTC)

Crotamiton - frequent treatment failure reported, adults only

Ivermectin - one time oral dose, for those who cannot tolerate permethrins

Question 30

Permethrin 5% for scabies administration/counseling

Answer 30

Cream should be applied from the neck down to soles of feet

Leave on for 8-14 hours then wash off

All family members should be treated

Symptoms may persist for up to 2 weeks post treatment

Retreat after 1 week - because it is unclear if eggs are killed or not

Question 31

Permethrin 5% can NOT be used in which patients?

Answer 31

Infants under 2 months