Headlice and scabies Flashcards
(23 cards)
what is a parasite?
an animal living in or on another body which gains advantage from the host
what are two types of parasites ?
ENDOPARASITES:
- found within the body of the host
- protozoa, helminths
ECTOPARASITES:
- found on the outside of the host
- lice, mites
explain etoparasites?
Zoological class: arthropoda (animals with jointed feet) Divided body (segments) and hard exoskeleton 2 groups: Insects 3-segment bodies E.g. louse Arachnids 4 pairs of legs
what are lice
Ectoparasites that suck blood Mouth specialised for piercing skin and sucking blood 3 species Pediculosis capitus Pediculosis corporis Pediculosis pubis
what are symptons of body lice and treatment
SYMPTOMS:
- intense itching due to injection of saliva in body
- rash
- red bumps
- if untreated can lead to discolouration of skin
TREATMENT: - insecticides and symptomatic relief - hygiene measures - Bath/shower regularly - wash clothing at 50degress+ - Store contaminated clothing in closed container for over 2 weeks (no blood to feed upon) -Vacuum mattresses
what are the symptoms and treatment to pubic lice?
SYMPTOMS: - itching in the affected areas - inflammation or irritation in the affected areas caused by scratching - black powder in your underwear - blue coloured spots on your skin - tiny blood spots on your underwear or skin - nits/eggs stuck to hairs
TREATMENT:
- insecticides
- permethrin 5% dermal cream
- Malathion 0.5% liquid
- apply to whole body , leave overnight wash off after 12 hours
- repeat after 1 week
- wash clothing and bedding 50 degrees
- vacuum home
- all contacts to be treated the same
- avoid close contact until treated
how are lice transmitted
pubic lice - close contact, coitus, occasionally
clothing and bedding (by crawling
body lice- Transmitted via clothing-clothing contact or skin contact
head lice - Transmitted by head to head contact
detection method of head lice?
Wet hair method Wash hair as normal Put lots of conditioner Comb out tangles Using detection comb into roots of hair touching scalp draw down to tips of hair Comb all parts of scalp Check for lice after each stroke (wipe/rinse if seen) Rinse out conditioner Repeat procedure
Dry hair method Straighten untangle hair with comb Switch to detection comb Comb each section 3/4x Look for lice each time Trap lice with thumb, avoids risk of lice being repelled by static electricity as comb withdrawn from hair -Continue until full head covered
treatment of head lice?
Physical insecticides
Dimeticone 4% lotion/gel/spray (Hedrin ®)
Dimeticone 92% spray (NYDA®)
Isopropyl myristate and cyclomethicone solution (Full Marks Solution®)
Isopropyl myristate and isopropyl alcohol aerosol (Vamousse®)
Chemical Insecticides Require secondary application one week after to kill new lice (ovicidal efficacy unreliable) ADRs – irritation + erythema of scalp, hands Malathion 0.5% aqueous liquid (Derbac-M®)
Alternative
Wet combing using a Bug Busting comb and method
treatment no longer needed for head lice
Permethrin (Lyclear Crème Rinse®)
Evidence of resistance in the UK
Concerns that 10 minute contact time is insufficient
for efficacy
Phenothrin and Carbaryl
No longer available in UK
Essential oil-based treatments
Tea tree, eucalyptus, lavender, coconut oil
Lack of consistent evidence for safety and efficacy
Electric combs
describe the medicine malathion
(Derbac-M®) Available as liquid, lotion or shampoo No alcohol Licensed in pregnancy/bf Skin irritations can occur Cure rate between 33-75% reported in trials Reports of resistance Reluctance to use traditional chemical insectide Unpleasant smell
describe the medicine demiticone
Silicone based product (Hedrin®)
Physical insecticide – blocks the tubes lice use
to breathe and pass out water
Less likely to develop resistance
Good safety record + well-tolerated
Some reports of skin irritation
Odourless
Apply to dry hair and leave overnight (min 8 hrs)
Now there is 1 hr preparation
Does not kill unhatched eggs
Therefore two applications needed (7 days apart)
Cure rates of 70% reported in UK trials
Hedrin® brand has most trial data
Dimeticone
Full Marks Solution®
Dissolves wax coating on louse
exoskeleton, leading to dehydration anddescribe the medicine Isopropyl myristate cyclomethicone
Full Marks Solution® Dissolves wax coating on louse exoskeleton, leading to dehydration and death Apply to dry hair and leave for 5-10 mins Comb hair to remove lice Wash with shampoo to remove solution Repeat process after 7 days Suitable for asthmatics Odourless Over 2 years Ovicidal activity unknown Cure rates in trials vary from 52-82%)
describe Isopropyl myristate & isopropyl
alcohol (Vamousse®)
Lack of trial data on its use Contains alcohol 2 years + 15 minute application on dry hair No need to reapply
what are scabies
- ectoparasites
- arachnid
- sarcpotes abiei
Caused pruritic infections in humans
Romans used ‘scabies’ to describe any itchy skin
disease
Scabies is a pruritic skin condition caused by
‘Sarcoptes scabiei’ mite
how are scabies transmitted
Mite transmitted by close physical contact (e.g. holding hands, hugging or sexual contact)
Transmitted only via direct skin contact.
Crusted
Scabies can be transmitted via bedding,
towels, clothes and furniture
symptoms and treatment of scabies
symptoms: - Itching, rash Itching occurs weeks after infection and post -eradication Papular rash Presence of burrows Tracks made by mite burrowing through skin Small grey/silvery curved lines in skin (≤1 cm)
Crusted scabies: Clean the floors in your house and thoroughly vacuum your carpets and furniture, including the armchairs and sofa Clean all bed linen at high temps (50oC or over) after first treatment (mites lives for 1 day after) If unable to wash certain items, place them in a plastic bag for at least 72 hours. After this time, the scabies mites will have died.
describe how permethrin and treat scabies
Permethrin (Lyclear® Dermal Cream)
5% cream (different to head lice Tx)
Adults & babies >2months but <2 years should be ideally be
prescribed
Over 12 year olds should use a
full tube as a single application
(some patients 2 tubes)
Apply to whole body (ex. head – manufacturer)
Wash body after 8-12 hours
Preferred product as trials show it has the highest cure rate
(>90%) and minimal S/E
Permethrin
Malathion (Derbac M®)
0.5% non-alcoholic liquid (same prep used in head
lice)
Apply to whole body
Leave on for 24hdescribe how malathion can treat scabies
Malathion (Derbac M®)
0.5% non-alcoholic liquid (same prep used in head
lice)
Apply to whole body
Leave on for 24h
Case reports suggest approx 80% cure rate but not
many trials conducted
describe how benzyl benzoate can treat scabies
Benzyl benzoate (Ascabiol®)
Older preparation
Same application as before
2nd application after 5 days or can be applied
on 3 occasions at 12hr intervals
Avoid in children
Main problem is S/E – skin irritation and
transient skin burning (usually mild)
Less effective than malathion or permethrin,
not much solid evidence
what are threadworms
Endoparasite Also known as pinworm Enterobius vermicularis UK – Threadworm causes incontinence and embarrassment rather than morbidity Social stigma - lack of hygiene Need reassurance that condition is common and nothing to be ashamed about
Transmitted mostly via faecal –
oral route, also
retroinfection
inhalation occasionally
symptoms and treatment of threadworms
Usually none Severe cases may have diarrhoea Referral Fever with bedwetting or pain on urinating Vaginal discharge (eggs laid in vaginal area) Vomiting Severe diarrhoea Unexplained weight loss Travel abroad (other worms)
treatment
how to treat threadworms
Mebendazole
Inhibits worms uptake of glucose
Ovex® (OTC) or Vermox® (POM)
100mg tabs or suspension
≥ 2 year olds
6month-2year can be prescribed (unlicensed)
All household members treated at same time
Need to treat all family at same time and repeat
after 14 days if infection persists (debatable if it
should be routinely given)
Avoid in pregnancy/bf
Fairly safe to use
Limited trial data from old, small studies
