Lice and Scabies Flashcards
(100 cards)
1
Q
What are head lice risk factors?
A
most school age children m
hair length? not huge association
hygiene? no
ethnicity? maybe
2
Q
What are pubic lice risk factors?
A
Sexually active (requires close contact for transmission)
3
Q
What are body lice risk factors?
A
poor hygiene
overcrowding
poverty
4
Q
Head lice transmission?
A
direct head to head contact
formats (uncommon: hats, hair accessories, brushes
5
Q
Pubic lice transmission?
A
sexual or close body contact
shared clothing and bedding (uncommon)
6
Q
Body lice transmission?
A
shared clothing and bedding (the lice are living in the seams of clothing)
7
Q
Head Lice symptoms: prutitis (itchy skin)
Location?
Timeline?
Assessment questions?
A
Location - all along the occipital region, where it is warm
Timelime - if you’ve had life before, symptoms could appear in a day or two. if you’ve never had lice before, it could take 2-4 weeks to develop symptoms
Assess - you want to assess for close contacts; secondary symptoms (infections)
8
Q
what causes the pruritus (itching)?
A
saliva and faces that the lice excrete
9
Q
How do you distinguish lice from dandruff?
A
For flakes (dandruff) it can be removed easily
for lice, you can not remove it easily
10
Q
Diagnosis of lice
Diagnosis requires ____?
what is the most reliable method of detection?
A
detection of a live louse
most reliable method of detection is “wet combing”
11
Q
Describe the 7 steps in the wet combing technique
A
- apply plenty of conditioner from scalp to ends of hair
2.comb hair with a regular comb to remove tangles - switch to a lice comb. comb through hair starting with comb flat against the skin of the scalp. (it might help to separate the hair into sections with clips)
- after each comb, wipe the comb teeth with piece of paper towel
- check the paper towel for lice and eggs
- do this until the whole head has been combed through
- rinse out conditioner
12
Q
How long does it take to thoroughly check a head for lice?
A
20-30 minutes
13
Q
If there are head lice you will find ___or more lice on the comb
A
1
14
Q
what are the 5 signs and symptoms of body lice?
A
pruritus (often nocturnal)
bite marks (waist and axillae)
excitations
potential secondary bacterial infection
lice and nits in seams of clothing
15
Q
what is the type of lice that can spread the disease trench fever?
A
body lice
16
Q
Trench fever.
common in _____world war
caused by _____
cases in canada associated with ___
A
First World War
caused by Bartonella Quintana transmitted by body lice
homelessness
17
Q
Name 7 signs and symptoms of pubic lice
A
- pruritus (itchiness)
- papules, maculae ceruleae (bite marks,)
maculae ceruleae = discolered area of skin, blueish - excoriations (a raw irritated lesion caused by wearing off of the skin, caused by scratching)
- brown flecks or red spots on skin or undergarments
- presence of nits and lice
- location: pubic area, other areas of coarse hair
- risk of secondary bacterial infection
18
Q
What are 5 differential diagnosis of head lice?
A
1.dandruff
2.seborrheic dermatitis
3.accumulation of hair cosmetics
4. pseudo-nits
5. psychogenic itch
19
Q
What are 3 differential diagnosis of pubic lice?
A
1.seborrheic dermatitis
2.folliculitis
3.dermatophytosis (jock itch)
20
Q
What are 6 differential diagnosis of body lice?
A
- seborrheic dermatitis
- folliculitis
- atopic dermatitis
- impetigo
- flea or insect bites
- scabies
21
Q
Scabies
highly contagious infestation of the skin by _______
epidemics occur in ______
most common in _____
A
Sarcoptes Scabiei
crowded living conditions and institutions
children and elderly
22
Q
Scabies transmission?
A
prolonged skin to skin contact
fomites
23
Q
what are 4 signs and symptoms of scabies
A
1.intense pruritus (itchiness), worse at night
2. primary lesions (burrows, vesicles, papule)
-papule is pimple like
-burrows appear as tiny raised and crooked (serpiginous) grayish-white or skin-colored lines on the skin surface
-vesicles are like tiny blisters
3. secondary lesions
4. mite eggs and faces on skin scraping (required for diagnosis)
24
Q
When do scabies symptoms develop?
A
1st time - take about a month to six weeks
2nd time - quicker response
25
What are some differential diagnosis for scabies? list 5
seborrheic dermatitis
eczema (atopic dermatitis)
impetigo
body lice
bed bugs/insect bites
26
Is lice self- treatable?
yes it can be treated without consulting a doctor
encourage physician visit for those with pubic lice (could be at risk for other STIs)
27
Is scabies self-treatable?
patients without a confirmed diagnosis or exposure to known scabies case should be referred for diagnosis
-scabies is really transmissible
28
Red flags of scabies/lice
presence of secondary bacterial infections
resistant/recurrent cases where self-care options are no longer viable
diagnostic uncertainty
29
what are the 4 goals of therapy of lice and scabies?
1.exterminate/get rid of infection
2. relieve symptoms
3. prevent secondary infections
4. prevent spread
30
Lice - Permethrin 1% and 5%
brand name
mechanism of action
indication
NAPRA schedule
pediculicide activity (kill activity)
Ovicidal activity (kill eggs)
efficacy/cure rate
cost
Nix, Kwellada P
insecticide, respiratory paralysis
head + pubic lice 1%
scabies 5%
schedule 2
yes pediculicide activity
70-80% ovidical activity
50-97% efficacy/cure rate
cost 17$/59mL
31
Lice - Pyrethrin with Piperonyl Butoxide (PPB)
brand name
mechanism of action
indication
NAPRA schedule
pediculicide activity (kill activity)
Ovicidal activity (kill eggs)
efficacy/cure rate
cost
R&C
insecticide
respiratory paralysis
head + pubic lice
(scabies off label)
schedule 2
yes it has pediculicide activity (but less than permethrin)
70-80% ovicidal activity
12$/50ml
32
Lice - Isopropyl myristate 50%
brand name
mechanism of action
indication
NAPRA schedule
pediculicide activity (kill activity)
Ovicidal activity (kill eggs)
efficacy/cure rate
cost
Resultz
Noninsecticidal
dehydration
head lice
schedule III (self selection in pharmacy)
pediculicide activity - yes
ovicidal activity - no
efficacy/cure rate - 54-82%
cost 18$/120ml
33
Dimeticone 50%
brand name
mechanism of action
indication
NAPRA schedule
pediculicide activity (kill activity)
Ovicidal activity (kill eggs)
efficacy/cure rate
cost
NYDA
noninsecticidal
suffocation
head lice
schedule III (self selection in pharmacy)
pediculicide activity (yes but limited studies)
ovicidal activity - yes
efficacy/cure 70-97%
cost 29$/50ml
34
Pyrethrin/Permethrin resistance
resistance patterns are highly variable from _____ to _____
from community to community
35
what are two possible mechanisms of resistance to neurotoxins =?
kdr (knockdown resistance): mutation in sodium channel gene that decreases neuronal sensitivity to these agents
increase levels of degenerating enzymes (glutathione s-transferase and monooxygenase)
36
Permethrin
Contraindications
side effects
systemic absorption
-Allergy: ragweed or chrysanthemum
-itching, burning, stinging, redness
-minimal
37
Pyrethrin/Piperonyl Butoxide
Contraindications
side effects
systemic absorption
-Allergy: ragweed or chrysanthemum
-itching, burning, stinging, redness
-minimal
38
Isopropyl Myristate
Contraindications
side effects
systemic absorption
-Allergy to ingredients
-Caution: open flames
-local irritation and redness, avoid contact with eyes
-minimal
39
Dimeticone
Contraindications
side effects
systemic absorption
-allergy to ingredients
-caution: open flames
-local irritation/itching
-ocular irritation
-systemic absorption: NONE
40
Permethrin
Pregnancy
Lactation
Pediatrics
-drug of choice
-drug of choice
>2 years (read product label)
>2 months (read guidelines)
41
Pyrethrins/Piperonyl Butoxide
Pregnancy
Lactation
Pediatrics
-drug of choice
-drug of choice
>2 years (read product label)
>2 months (read guidelines)
42
Isopropyl myristate
Pregnancy
Lactation
Pediatrics
Pregnancy - safety unknown
Lactation - safety unknown
>2 years (product label)
>4 years (guidelines)
43
Dimeticone
Pregnancy
Lactation
Pediatrics
Pregnancy - safety unknown (no systemic absorption)
lactation - safety unknown (no systemic absorption)
>2 years (product label and guidelines)
44
Lice treatment
diagnosis of lice
asess and screen close contacts
select appropriate treatment
non pharmacological (mechanical removal, treat personal environment)
retreat in 7-10 days
45
Who should be treated?
1. close contacts should be inspected for lice and all infested contacts should be treated at the same time to prevent re-infestation
2. bedmates should be treated
3. no child should miss school because of lice (they've had it for weeks, dont need the stigma)
46
what are 5 non pharmacological management for lice?
1. nit and lice removal with nit comb
2. avoid sharing personal items that are in contact with infested area
3.items in prolonged contact with head in the last 2 days should be washed, stored in sealed plastic bag for 10-14 days
4. soak combs and brushes in hot water for 10 minutes
5. vacuum furniture
47
what are 5 considerations when choosing a pharmacological treatment agent?
1.product efficacy (local resistance?)
2. ease of administration
3. safety considerations/patient characteristics (red flags, allergies, age, contraindications, etc)
4. cost
5. patient preference
48
Permethrin
Cost
Hair starts
Quantity
application
contact
directions
reapply when
17$/59ml
towel dried
short hair 30ml
long hair 59ml
shake well, saturate hair and scalp
leave on for 10 minutes
rinse
remove nits
reapply in 7-10 days
49
Pyrethrin Piperonyl Butoxide
Cost
Hair starts
Quantity
application
contact
directions
reapply when
12%/50ml
dry
Short 25 ml
Long 100 ml
saturate hair, massage into scalp
leave on for 10 minutes
add small amounts of cool water, massage until lather forms, rinse
remove nits
reapply in 7-10 days
50
Isopropyl Myristate
Cost
Hair starts
Quantity
application
contact
directions
reapply when
18$/120ml
dry
short 30-60ml
med 60-90 ml
long 90-120
saturate hair, massage into scalp
leave on for 10 minutes
rinse
remove nits
reapply in 7-10 days
51
Dimeticone
Cost
Hair starts
Quantity
application
contact
directions
reapply when
29$/50 ml
dry
short 10ml
medium 18ml
long 22ml
very long 34 ml
screw pump on. spray hair to saturate and massage into scalp.
leave on for contact for 30 minutes, +8 hours overnight
DO NOT RINSE
remove nits
then wash out with normal shampoo
52
what should you consider when head lice treatment fails?
misdiagnosis, improper application, reinfestation, resistance
53
treatment failure after adequate trials from at least ___different pharmacological classes should be referred
two
54
How do we know when treatment fails?
when we are seeing live lice again
55
When PROPERLY applied treatment fails, switch to a product in a ___pharmacologic class
different
56
What are three possible alternative therapies when standard therapy fails?
1. oral ivermectin: 200mcg/kg, two doses given 7-10 days apart (cost 150$)
-caution in children less than 15kg
-likely safe in pregnancy and lactation
2. topical ivermectin - 1% cream applied to dry hair and rinsed after 10 minutes (200$)
3. Permethrin 5% left on hair overnight covered with a plastic shower cap
57
OTHER head lice treatments
-manual removal only (nit busting)
-occlusive agents (petroleum, cetaphil cleanser, mayonnaise, olive oil; limited evidence)
58
Methods to avoid
-treatments including sulfa/trim (lack of evidence, antibiotic resistance)
-furniture and household sprays (may contain permethrin)
-essential oils (evidence does not support use, potential for adverse effects)
-wash out for product extensions (they are no longer the original product or related to)
59
what are 4 treatments of pubic lice
1. Permethrin 1% or PPB (apply to affected areas, wash off after 10 minutes, second treatment in 7-10 days)
2. Education: lice and nit removal, avoid sex, refer for SiT
3. sexual contact within the previous month should be informed and treated
4. eyelash involvement (apply ocular grade white petroleum twice daily for 10 days)
60
List three treatments of body lice
1. pharmacological agents are unnecessary because the lice do not live on the body
2. hygienic measures treatment of choice (bath, seal items in plastic bags, etc)
3. if patients have numerous body lice that are adherent to body hairs, treatment with permethrin 5% (applied for 8-10 hours to entire body) may be considered
61
Who should receive scabies treatment?
definitive diagnosis should be ensured prior to treatment (infestation of the patient or a closes contact should be confirmed)
infested persons, household members, and sexual partners from the previous month should be treated at the same time
62
What are 5 nonpharmacological treatment and prevention of scabies?
1.wash clothing, bedding and towels from the last 3 days in hot water and dry in hot dryer
2.store unwashed items in plastic bags for 7 days
3. vacuum rugs and furniture
4. trim fingernails
5. avoid body contact with others until treatment is complete
63
What are three topical treatments of scabies?
1. Permethrin 5%
-most effective (recommended for >2 months; available in cream or lotion)
Second line options include
2. topical sulfur 5 to 10%
(prevents respiration in insects, limited data; preferred treatment in infants <2 months)
3.Crotamiton 10% (less effective than permethrin and resistance reported)
64
How to treat resistant scabies?
oral ivermectin 200 mcg/kg as a single dose
repeat in two weeks
65
How to treat crusted scabies?
oral ivermectin 200 mcg/kg as a single dose on days 1,2,8,9, and 15
AND topical permethrin 5% full body application daily X 7 days
66
How to treat institutional outbreaks of scabies?
topical treatment of everyone with permethrin 5% if feasible or else
treat all with oral ivermectin 200 mcg/kg, repeat in 7-14 days
67
How to apply permethrin 5%?
1. apply to a clean, COOL, dry skin
2. massage cream into skin from neck to soles of feet, pay attention to the creases, put on clean clothes
3. if hands are washed - reapply
4. remove after 8-14 hours by showering. dress in clean clothes
5. reapply 7 days later only if necessary (live mites, new lesions)
For infants only: apply to scalp, forehead and temples
68
Treatment of scabies using Nix (permethrin 5%) dosing (30g tube)
adults and children >12 years: 30 g tube
children 5-12 years 15g tube
children 2-5 years 7.5g
<2 years 4-7g
consider obese...
69
How often should the patient monitor for lice and nits and what should be the endpoint of treatment?
should be monitored daily for two weeks; decreased or none after 1st treatment and none after 2nd treatment
70
how will the patient know if the lice has been eradicated?
if all of the lice are dead within 24 hours of treatment
71
How often should the patient monitor for pruritis,(itchy skin) lesions and infection and what should be the endpoint of treatment?
should be monitored daily by the patient for 2 weeks, and the itch should be resolved in 2-3 weeks. lesions should clear up within 1 week, there should be no infection
72
what side effects and allergic reaction should the patient be on the lookout for? How to manage the side effects?
side effects: itching, redness, burning/tingling - should be resolved within one hour of treatment, if severe contact a health care provider
consider a topical corticosteroid or antihistamine, cool compress after treatment
73
What is the scientific name for head lice? For pubic lice? for body lice?
head lice = pediculus humanus capitis
pubic lice = phthirus pubis or "crabs"
body lice = pediculus humanus corporis
74
What is the appearance of nits/eggs?
<1 mm in length, yellow-brown to grey-white, dots or ovals
75
What is the appearance of the lice (louse)?
2-4mm in length, with 3 pairs of legs, grey white to tan brown, darker after feeding, no wings
76
Life cycle of the nits/eggs?
6-10 days to hatch
77
Life cycle of the louse (head lice)?
live up to how many days on the scalp?
females lay how many eggs per day?
infestation involves how many live lice?
become adults 7-15 days after hatching. adults live up to 30 days on the scalp
females laying 5-10 eggs per day
involves 5-10 live lice
78
What is the survival time away from host of the nits/eggs and the louse/lice?
the nits/eggs may survive up to 30 days but will not hatch if <22C
blood meal is needed upon hatching to survive
the louse may live 1-2 days away from the host
79
What causes the lesions and symptoms experienced of head lice?
Primary: hypersensitivity to louse saliva or feces; papule around the ears, face and neck, pruritic scalp
Secondary: excitations, crusts, pustules with secondary infections
80
What causes the lesions and symptoms experienced of pubic lice?
primary: hypersensitivity to louse saliva or feces; including papule, pruritus in the genetial area, possibly small brown specks on undergarments due to lice excreta
secondary: excoriations, crusts, pustules with secondary infection; blue grey skin discolouration
81
What causes the lesions and symptoms experienced of body lice?
Primary: hypersensitivity to louse saliva or feces; including papule, pruritus (worse at night), particularly around the neck, waist and axillae
secondary: linear excoriations, crusts, pustules with secondary infection
82
Location of lice/nits of head lice
scalp hair, warmer parts of the head, nits are at base of shaft
83
location of pubic lice
pubic hair, nits are at base of hair shaft
84
location of body lice
seams of clothing close to the body where it is warmer
85
How to diagnose head lice?
diagnosis requires detection of live lice on scalp
86
How to diagnose pubic lice?
detected in the hair of the affected area
-it is considered a sexually transmitted infection
87
How to diagnose body lice?
Live lice are detected in the seams of clothing
88
in head lice, after treatment ,___ willl remain attached to the hair. ___should be mechanically removed with a fine tooth comb after any pharmacologic treatment to minimize chances of self-reinfestation
nits; nits
89
what is one agent that can be used to loosen nits so that they slide off the hair shaft more easily?
vinegar
90
what pharmacological agents are used for pubic lice
permethrin 1% or pyrethrins with piperonyl but oxide
91
How to treat persistent itching caused by a pediculicide?
oral histamine or topical corticosteroid
92
What is the pathophysiology of scabies?
a highly contagious infestation of the skin with the microscopic human mite, sarcoptes scabies var. hominis; cycles of epidemics every 7-15 years in crowded living conditions and in institutions; infected persons have hundreds of thousands and this infection carries a high mortality rate due to secondary infections and sepsis
93
What is the appearance of scabies?
not usually visible to the human eye but may appear as tiny black of white dots on the skin, no wings
94
How do we determine that a person has scabies?
by mounting scrapings from non excoriated burrows, papules or vesicles in potassium hydroxyde onto a slide and examining directly under microscope. any sign of a mite, eggs or fecal material is a positive test
95
what is the life cycle of the scabies?
how many eggs a day do they lay?
lifespan?
female burrows create a tunnel in the uppermost layer of the epidermis, depositing faces along their pathway, laying 2-3 eggs a day; lifespan 1-2 months
96
lesions and symptoms of scabies
pruritus (intense pruritus) which is worse at night
Primary lesions: linear or wavy silvery lines (burrows)
Secondary lesions: staph aureus or street progenies leading to pustules, furunculosis and impetigo
97
Lesions and symptoms of scabies include pruritus. How long could the inflammatory response persist for?
4-6 weeks
98
Distribution of scabies (where is it found on the body)
fingerwebs, wrists, sides of hands and feet, axillae, groin, areola, nipples, belt line
99
Transmission of scabies
personal contact, particularly sexual contact
100
differential diagnosis of scabies
flea or insect bites
atopic dermatitis
seborrheic dermatitis
impetigo
