Infestations Flashcards
What are head lice
Human pathogen
Head-to-head contact
Live on scalp, lay eggs
Suck blood for nutrition
Inject saliva into scalp (itch)
School-age children
Lifecycle of head lice
Completed on human head
Die off without head
Eggs need warmth and moisture
Lice need warm, moisture, and food
What are scabies
Human pathogen spread by skin-skin contact
Not from animals
Invasion of uppermost skin layer (stratum corneum)
Mite burrows into site
Females lay 1-3 eggs per day and extend burrow daily
Common in school-aged children, Aboriginal communities, and nursing homes
Spread to whole family if untreated
What are crusted scabies
Norwegian scabies
Infections w/ over a million mites
Immunosuppressed or institutionalised people
Thick crust forming on feet and scalp
Misdiagnosed as psoriasis, seborrhoeic dermatitis.
Extremely infectious and requires oral ivermectin
Signs and symptoms of head lice
Eggs (nits) and live, moving mites on hair
Itch and irritation from feeding
Several weeks to develop after initial infestation
Scratching causes crusting and scaling
Small sores w/ tender glands in neck = secondary bacterial infection
Unhatched = dark area w/ shell
Hatched= transparent
Scabies signs and symptoms
Mites or eggs at burrows
Itch, worse at night or after hot shower
5 weeks to sensitise
Itch does not occur following initial infestation
Itch sooner after subsequent infestations
Burrows have linear rash/ridge, noticable on wrist and fingers, papular and erythematous lesion near scratch
Treatment of head lice
Wet combing method - lather hair with conditioner daily or every second day for 10–14 days until no lice
Malathion 0.5%, 1% (children>6mths) - KP24 lotion or foam. Apply to dry hair, lotion for 12 hrs, foam for 30 mins
Pyrethrins 0.165% + piperonyl butoxide 1.65% - banlice or pyrenel. Leave for 10 mins, spray on dry hair, foam on damp hair.
Isopropyl myristate 50% w/w (full marks solution) - apply on dry hair for 10 mins
Dimeticone (nitwits, quitnits, hedrin) all ages - apply to dry hair and leave for 8 hrs. coat lice.
Benzyl alcohol (child>6mths) (neuralice advance) - apply to dry hair and leave for 10 mins. suffocate lice.
Herbal/essential oils (children>6 months) (neutralice, moov).
Repeat treatment after 7 days
Explain the wet combing method
Good for pregnant and breastfeeding women, babies, allergies, asthma, or open wounds.
- comb hair conditioner onto dry detangled hair.
- comb sections of hair w/ fine tooth head lice comb.
- wipe conditioner from comb onto paper towel or tissue.
- check tissue and comb for lice and eggs.
- repeat combing for all of head 4-5 times.
- if lice/eggs found, treat person.
Resistant head lice cases
Repeat treatment using another insecticide or wet comb
Treatment failure = ivermectin for adults/child 15kg+ 200mcg/kg oral w/ fatty food as a single dose, repeat in 7 days.
Failure because:
- not enough product
- not repeating after 7 days
- reinfestation
Scabies Treatment
Permethrin 5% cream (lyclear) - 1st line. apply from chin down (except if elderly), leave for 8 hrs/overnight, reapply to hands if washed.
leave for 24 hrs if treatment failure
Repeat in 7 days.
Benzyl benzoate 25% lotion - more irritating, test dose first, apply chin down and wash after 24 hrs.
Undiluted for adults, dilute for children.
Repeat in 5-7 days.
Topical crotamiton 10% cream (eurax) - helps w/ itch. don’t wash off. less effective. apply for 2-5 days.
Sedating antihistamine - helps w/ itch
After effective treatment, moderately potent corticosteroid can relieve itch
Resistant scabies treatment
Ivermectin tablets 3mg - PBS authoritty for failed topical treatment or crusted scabies
Dose varies:
typical scabies = dose on days 1,2,8
crusted = days 9,15,22,29
use w/ topical treatment
Referral for head lice
Secondary infection signs
Treatment failure
Unclear diagnosis
Referral for scabies
Severe infection
Situated in endemic area
Treatment failure
Unclear diagnosis
Lifestyle changes for head lice
Wash pillows on hot cycle and combs/brushes in hot ater
Check family and close contacts, only treat if live lice are found
School notified
Kids can go to school if treated day before
Lifestyle changes for scabies
Underwear, night clothes, bath towels, bed linen used in last 3 days washed in hot water and dry cleaned
Soft toys and doonas exposed to UV light for hours
Contacts treated at same time
Follow up 4-6 weeks after treatment
Failure from poor understanding of treatment
