Infestations Flashcards
What is scabies?
Sarcoptes scabeii
Highly contagious, common disorder particularly in children and young adults?
How do scabies spread?
Direct person to person contact - holding hands, sharing bed
Female mite digs button - a short wave grey or red line on the skin and lays eggs which hatch as larvae.
The itch and subsequent red rash is probably due to allergic sensitivity to the mite or its products - delayed type IV hypersensitivity
What are signs of scabies?
Itchy papules, vesicles, pustules, and nodules affected finger-webs, wrists flexures, axillae, abdomen (esp. around the umbilicus and waistband area) buttocks, groins
(Itchy red penile or scrotal papules are diagnostic)
In young infants - palms and soles are involved
Eruption is usually excoriated and becomes eczema
Eggs can be seen in skin scrapings under microscope
What is management for scabies?
Permethrin 5% is first-line
- apply to all parts of body from neck down, wash off after 8-12h
- Apply once weekly for 2 doses
- IF hands are washed with soap within 8h of application, reapply
Malathion 0.5% is second-line
Give appropriate guidance on use
Pruritus persists for up to 4-6 weeks post eradication
What advice for scabies treatment?
Avoid all close physical contact with others until treatment is complete
All household and close physical contacts should be treated at the same time, even if asymptomatic
Launder, iron or tumble dry clothing, bedding, towels on the first day of treatment to kill off mites
What are instructions for scabies treatment?
Apply insecticide cream or liquid to cool, dry skin
Pay close attention to areas between fingers, toes, under nails, armpit area, creases of the skin such as wrist and elbow
Allow to dry and leave on skin for 24h before washing off
Reapply if it is removed during this time
Repeat treatment 7d later
When are crusted scabies seen? Treatment?
Patients with suppressed immunity, HIV
Ivermectin is treatment of choice and isolation is essential
What are headlice? How do they spread?
Pediculus wapitis
Lice are 3mm long and have legs adapted to ling to hair shafts Eggs (nits) are bound firmly to the scalp hairs and when empty appear white.
Spread is only by head to head contact
What are signs of headlice?
Usually asymptomatic
Itch ± papular rash on the nape
What is maangmgent for headlice?
All require 2 applications 7 days apart
Malathion
Dimeticone
Isopropyl myristate and cyclomethicone
When should you treat for head lice?
Only if 1 or more live lice are seen on combing
What are crab lice? MAnagmgnet?
Phthiriasis pubis
Sexually transmitted and affect pubic hairs
Topical malathion or permethrin to all affected areas
Wash off after 12h and repeat after 7d
