Treatment of Scabies:Permethrin vs. Ivermectin

A04

義大醫院王柏欣 , 陳奕峰 , 詹子慶

Transmission of scabies

Mite Sarcoptes scabiei, skin to skin contact Typical vs atypical/crusted/keratotic 2-6 weeks before symptoms are apparent During the incubation period the newly

infested healthcare worker could be a source of transmission

Prevention and Control

Recognize patient with symptoms and signs Skin scrapings Contact isolation precautions Personal protective equipment

Pharmaceutical agents : Lindane: standard tx, but resistance Permethrin vs Ivermectin

Thinking Process

Inadequate treatment of scabies increase transmission of scabies throughout hospitals

Find a more effective treatment among choices of medication

Permethrin vs Ivermectin

Search form evidence-based medicine database for answer

Permethrin vs IvermectinWhich is better for scabies treatment?

Ask an answerable question

PICO

Patient Scabies infected patient

InterventionMedical treatment with Permethrin

ComparisonMedical treatment with Ivermectin

Outcome Prevention of scabies outbreak

Tracking Down the Best Evidence

Cochrane Database of Systemic Reviews PubMed Library Clin-eguide

Tracking down the best evidence

Database: Cochrane Database of Systemic Reviews Key Word: scabiesResult:

[Review]

Interventions for treating scabies

M Strong, PW Johnstone

Cochrane Database of Systematic Reviews 2008 Issue 2

(Status: Edited)

Database: Clin-eguide Key Word: scabiesResult:

A comparative study of oral ivermectin and topicalpermethrin cream in the treatment of scabies

Journal of the American Academy ofDermatology - Volume 42, Issue 2 (February2000)  -  Copyright © 2000 American Academy ofDermatology, Inc.

Tracking down the best evidence

Permethrin acts by disrupting the sodium channel current

Topical application ensures maximum concentration of the drug in the skin

Infrequently used because of its high cost

Ivermectin bind selectively to GABA gated chloride ion channels, which occur in nerve and muscle cells

not be effective against the younger stages inside the egg because the nervous system has not yet developed

Additional doses needed

Single application of permethrin was superior to

a single oral dose of ivermectin by 2 weeks

(P < .001).

Database: PubMedKey Word: scabiesResult:

2001 National Guideline on the Management of Scabies Evidence Base Medline search strategy Years covered 1966-1997 Key terms - scabies/th, scabies/dt, lindane/tu,

permethrin/tu, malathion/tu.

Tracking down the best evidence

Permethrin 5% cream (level of evidence 1b, grade of recommendation A)

Malathion 0.5% aqueous lotion (level of evidence 4, grade of recommendation C)

These should be applied to the whole body from the neck downwards, and washed off after 12 hours, usually overnight.

Itch may persist for several weeks. Application of crotamiton cream may give symptomatic relief. Antihistamines may also be helpful in relieving itch. Potentially contaminated clothes and bedding should be washed at

high temperature (>50°C) if possible. Mites separated from the human host die after 72 hours.

Oral ivermectin in a dose of 200 mcg/kg in the treatment of Norwegian scabies.

Ivermectin is not licensed for this purpose in the UK There have been concerns about toxicity

Pregnancy and Breastfeeding Permethrin is safe during pregnancy or breastfeeding

Thank you for listening!!