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Wednesday, June 30, 2021

Scabies 2021

Classical scabies
Indications
Recommended therapy
Alternative therapy
Infants
< 2 months
Sulphur 6% in petroleum ointment base / calamine
·        For 3 days, rinse off after 24 hours then reapply
·        Treat whole body including the face (avoid eyes and mouth)
·        Bath taken in between application
Crotamiton 10% 
     Apply once daily for 5 days 1,2,5,8
Children
2 months
 - 2 years
*Permethrin 5% (NOT available for JPL)
·        Apply from neck down to the soles of feet, wash off after 8-14 hours
·        1 application is generally curative2
·        If there is any signs of new mites, repeat application after one week2.
Sulphur 6% in petroleum ointment base / calamine OR Sulphur 10-25% compound
·        For 3 days, rinse off after 24 hours then reapply
·        Treat whole body including the face (avoid eyes and mouth)

Crotamiton 10%
              Apply once daily for 5 days 1,2,5,8
Children
2 - 12 years
Benzyl benzoate (EBB) 12.5%
     Apply after bath, whole body neck and below
     Rinse off after 24 hours
     Apply for 2-3 consecutive days, with bath taken in between application
     Repeat application within 5 days for severe cases (rarely practised) 1,2,6
     Alternatively, 3 applications at 12-hourly interval (rarely practised) 2
·        Itching may persist up to 2 weeks after successful treatment. Avoid further treatment and consider topical corticosteroid2.
*Permethrin 5% (NOT available for JPL)
·       Apply from neck down to the soles of feet, wash off after 8-14 hours
·       1 application is generally curative2
·       If there is any signs of new mites, repeat application after one week 2,6,8. (Our CPG recommends for a repeat after 1 week)

Crotamiton 10%
·       Apply once daily for up to 5-7 days 1,2,5,8
Adults
> 12 years
Benzyl benzoate (EBB) 25%
·        Apply after bath, whole body neck and below
·        Rinse off after 24 hours
·        Apply for 2-3 consecutive days, with bath taken in between application
·        Repeat application within 5 days for severe cases (rarely practised) 1,2,6
·        Alternatively, 3 applications at 12-hourly interval (rarely practised) 2
·        Itching may persist up to 2 weeks after successful treatment. Avoid further treatment and consider topical corticosteroid2.
*Permethrin 5%
·       Apply from neck down to the soles of feet, wash off after 8-14 hours
·       1 application is generally curative2
·       If there is any signs of new mites, repeat application after one week 2,6,8. (Our CPG recommends for a repeat after 1 week)

Crotamiton 10%
·       Apply once daily for 5 days1,2,5
Pregnancy/ Lactation
Permethrin 5%
·       Apply from neck down to the soles of feet, wash off after 8-14 hours
·       1 application is generally curative2
·       If there is any signs of new mites, repeat application after one week 2,6,8. (Our CPG recommends for a repeat after 1 week)
Topical sulphur 6-33% [Uptodate: Scabies]
OR
Sulphur 10-25% compound [BMJ]
OR
6% sulphur in calamine/ petrolatum [Topical 2018]


*Permethrin is agent of choice due to ease, effectiveness and safety. The limiting factor in the use of permethrin is its cost and Prescriber Category1 7, 8

In general: 1
·       Topical treatment must be applied to the entire skin surface, from jawline downwards including all body folds, groin, navel and external genitalia, as well as the skin under the nails (especially crusted scabies).
·       In adults with classical scabies, treating the face is controversial, but in babies, the face must be treated, because transmission may occur from breastfeeding.
·       At any time during treatment, medications should be re-applied if it is washed off i.e. after hand washing.
·       If the treatment is applied by someone without scabies, this person should wear medical gloves during application.
·       Patients with scabies and their close physical contacts, even without symptoms, should receive treatment at the same time. Prescriptions must be provided for all household members and sexual partners.
·       After completion of treatment, patients should use fresh, clean bedding and clothing. If possible, potentially contaminated clothes and bedding should be washed at high temperature (>50°C) or kept in a plastic bag for up to 72 hours, because mites that are separated from the human host will die within this time period.
·       Immediate treatment for the patient (treat secondary infection first, as most scabicides are irritant). 8

Availability6
·           Permethrin 5% lotion (A/KK )
·           Crotamiton 10% cream (B)
·           Calamine with 6% Precipitated Sulphur Lotion (C)
·           Emulsion Benzyl Benzoate (EBB) 25% (C+)

Contraindications and side effects: 1
Medicine
Contraindication(s)
Side Effects
Permethrin 5%
-
Itching & burning/stinging sensation on application
Sulphur 6% in petroleum ointment base / calamine
-
o   Messy, malodorous, stain clothing
o   May cause irritant contact dermatitis
Crotamiton 10%
Avoid massive & prolonged use in pregnant women and infants
Irritant contact dermatitis
EBB 10-25%
·                     Pregnant women
·                     Breast feeding women
·                     Infants less than 2 years
o   Skin irritation and burning sensation.
o   May casue conjunctivitis if exposed to eyes.
o   May worsen/cause post-scabetic eczematous reaction.

Treatment of itch in scabies 1
·           Itching usually persists for about 1-2 weeks after successful treatment but it should be evaluated if prolonged.
·           Causes of persistent itching include cutaneous irritation, allergic contact dermatitis to medicaments, post-scabetic eczema or possible treatment failure.
·           The treatment includes:
       i.     Antihistamines (recommended for night dose): Chlorpheniramine, diphenhydramine (use with caution in < 2 years old).
     ii.                   Corticosteroids: topical or short course of oral steroids (depending on the severity).
    iii.                   Emollients: regular application of emollients for dry and eczematous skin.

References:
1.          CPG of Scabies in Adults and Children 2015
2.          Drug Information Leaflet
3.          www.uptodate.com
4.          Centres for Disease Control and Prevention (CDC)
5.          British National Formulary for Children, BNFC 76 (September 2018 – Mac 2019)
6.          Formulari Ubat KKM (Accessed online on 8 July 2019)
7.          Treatment of scabies: newer perspectives. Postgrad Med J 2005;81:7–11
8.          Pediculosis and Scabies: A Treatment Update. Am Fam Physician. 2012 Sep 15;86(6):535-541.
9.          Topical Preparations Counselling Guide for Pharmacist, 1st Edition, 2018
8.          BMJ Best Practice [Scabies, updated 19 June 2018]
9.          


Nodular Scabies
i) Children
<2 years
Crotamiton 10% (Medical Supervision)
·       2-3 times daily for 5-7 days 1,8
·       Add topical corticosteroids of mid potent to potent for a short duration of 2 weeks 1

ii) Children
<12 years
Crotamiton 10%
·       2-3 times daily for 7-14 days 1,8
Crusted scabies
> 2 years
(EBB)

> 5 years
(Ivermectin)


Permethrin 5%
·       apply daily for 7 days then twice weekly until cure2
·       Alternatively, 2-3 days for 1-2 weeks4
PLUS
Oral Ivermectin
·       PO 200 mcg/kg single dose and repeat after 2 weeks1
·       Not for children below 5 years old or <15kg, avoid in pregnant and lactating mother1
PLUS
Keratolytics
·       Apply keratolytic (salicylic acid ointment) to hyperkeratotic areas1
Oral Ivermectin
·       PO 200 mcg/kg single dose and repeat after 2 weeks1
OR
Benzyl benzoate (EBB) 25%
·       Several applications of benzyl benzoate1
·       Apply daily for 7 days then twice weekly until cure2


PLUS
Keratolytics
·       Apply keratolytic (salicylic acid ointment) to hyperkeratotic areas1

Availability:
·         Permethrin 5% lotion (A/KK )
·         Crotamiton 10% cream (B)
·         Calamine with 6% Precipitated Sulphur Lotion (C)
·         Emulsion Benzyl Benzoate (EBB) 25% (C+)

References:
  1. CPG of Scabies in adults and children 2015
  2. Drug Information Leaflet
  3. www.uptodate.com
  4. Centres for Disease Control and Prevention (CDC)
  5. BNF for Children (September 2015-2016)
  6. Formulari Ubat KKM (Accessed online on 8 July 2019)
  7. Treatment of scabies: newer perspectives. Postgrad Med J 2005;81:7–11