November 20, 2012

Q. Is it safe to use permethrin (Nix cream, Kwellada-P lotion) to treat a breastfeeding baby for scabies?

A. According to the manufacturer, permethrin should not be used in children less than 2 years of age(1); however, guidelines in Canada, the USA and Britain recommend permethrin 5% cream or lotion as the treatment of choice for scabies in infants 2 months of age and older.(2,3,4) It should be applied to the entire body including the head and face, left on overnight for 8 to 9 hours, washed off and treatment repeated in 7 days.(5) An alternative (but less convenient) treatment is sulfur 7% in petrolatum (Vaseline) applied to the entire body, left on for 24 hours, washed off and reapplied three times.(5) A third line alternative is crotamiton (Eurax) cream. It is not as effective as permethrin and there is less information about its use in infants.(6) Use cotton mitts or socks on the hands of infants and young children to prevent them rubbing the cream or ointment into their eyes.(7)

The mother must also be treated for scabies at the same time.(8) Although the use of permethrin by breastfeeding women has not been studied, it is considered the treatment of choice for breastfeeding women.(9,10,11) Because the drug is not well absorbed through the skin, very little ends up in the breast milk and it is recommended for scabies treatment with no interruption in breastfeeding. (9,10) The manufacturer suggests that breastfeeding could be temporarily stopped while the mother is being treated (1) but this can be very inconvenient and is not necessary. Wash the cream off the nipples before nursing and reapply after the baby is finished feeding. (12)

General information about scabies
Scabies is an infestation of the skin by a burrowing mite Sarcoptes scabiei. This infestation results in extreme itchiness in the areas of the skin where the mite burrows. The itching is usually more severe at night and is caused by an allergic-type reaction to the mite, mite waste and mite eggs. Signs of the burrows or tracks are most common in the folds of the skin, between fingers, in armpits, around the waist, along the insides of wrists, inner elbow, on the soles of feet, around breasts and in the groin, although almost any area of the body can be affected. The burrow is a thin, grayish, reddish, or brownish line that is 2 to 15mm long.

Scabies is spread by close physical contact and, less often by sharing clothing or bedding with an infected person. Therefore all members of a household should be treated if one person has symptoms. Dogs, cats and humans are all affected by their own distinct species of mite. Each species of mite prefers one specific type of host and doesn't live long away from that preferred host. So, humans may have a temporary skin reaction from contact with the animal scabies mite, but people are unlikely to develop full-blown scabies from pets.

Treatment
To reduce the risk of transmission or eliminate reinfestation all contacts of the scabies infested person, even if they have no symptoms, should be treated as well. This includes sexual and close personal or household contacts within the preceding month. Itching can go on for weeks after successful treatment. Continued itching is not necessarily a reason for retreatment. Antihistamines can be used to treat the itching.

Permethrin 5% (Nix, Kwellada-P)
The cream or lotion is applied two times with a week or so between each application. Permethrin is generally considered safe for children and adults of all ages, including women who are pregnant or breastfeeding.

Directions for Use: For External Use Only
1. Discontinue use of other topical medications and cosmetics during treatment.
2. Clean and dry skin.
Note: Do not take a hot bath before treatment.
3. Apply sufficient amounts of Nix dermal cream (30 g tube) or Kwellada-P lotion and thoroughly massage into the whole body, excluding the head and face (except in infants), paying special attention to creases in the skin, hands, and feet, between fingers and toes, underarms and groin as well as under fingernails. Put on clean clothes. Long-sleeved shirts, pants and mittens should be worn by young children to avoid contact with mouth.
4. Leave product on skin for 8 to 14 hours.
5. Wash off by taking a shower or a bath.
6. Change into clean clothes.
7. Scabies will be killed, but itching may persist. This is normal and does not necessarily mean that the treatment has failed.
8. One single application is effective in most cases. If necessary, a second application may be given 7 to 10 days after the first, but only if live mites can be seen or new lesions appear.
9. All clothing, bed linens, and towels used within the 2 days prior to treatment should be machine-washed in hot water and dried on dryer hot cycle for at least 20 minutes, or dry cleaned following treatment. Mattresses which have been used by an infested person should not be used for 48 hours. Toilet seats should be disinfected.

Crotamiton (Eurax)
This non-insecticide medication is applied once a day for two to five days. Your doctor may recommend it if your baby has scabies. Crotamiton is considered safe in pregnancy and breastfeeding. It may not be as effective as permethrin.

Directions for Use: For External Use Only
1. Take a bath or shower before using this medication. Remove scaly or crusted skin by rubbing gently. Then dry with a towel.
2. Massage a thin layer of the cream into skin from the chin down to the toes, including skin folds and creases, between the fingers and toes, and on the soles of the feet. Avoid applying crotamiton on the face, eyes, mouth, vagina, and any skin that is inflamed, raw, or oozing. Trim fingernails short and apply the medication under the nails since the mites often live there. You may use a toothbrush to apply the medication under the fingernails. Immediately after use, wrap the toothbrush in paper and throw it away. Do not use the same toothbrush in the mouth because it may lead to poisoning.
3. Apply the medication again after 24 hours.
4. Change clothing, towels, and bed sheets the next morning after each application. Wash all clothing, towels, and bedding that have been used in the 3 days before treatment and after each application in hot water and dry in a hot dryer (or dry-clean) to kill all the mites and prevent them from returning. Items that cannot be washed or dry-cleaned should be removed from contact with the body for at least 72 hours.
5. Take a bath 48 hours after the last application to remove the medication from your skin.

Prepared by Jean Macpherson BSP and Karen Jensen MSc, BSP (SDIS). Reviewed by Dr. Yvonne Shevchuk PharmD, FCSHP (College of Pharmacy & Nutrition).
November, 2012

Sources
1. e-CPS [Internet]. Ottawa (ON): Canadian Pharmacists Association; c2012. Nix Dermal Cream [product monograph]. Available from: http://www.e-cps.ca. Also available in paper copy from the publisher.
2. Canadian Paediatric Society [website]. Scabies management. Ottawa, ON: Canadian Paediatric Society; 2009. Available from: http://www.cps.ca/en/documents/position/scabies. Accessed Nov. 2012.
3. Centers for Disease Control and Prevention [website]. Scabies. Suggested guidelines. Atlanta, GA: Centers for Disease Control and Prevention; 2008. Available from: www.cdc.gov/scabies/hcp/index.html. Accessed Nov. 2012.
4. United Kingdom National Guideline on the Management of Scabies infestation (2007). Available at http://www.bashh.org/documents/27/27.pdf. Accessed Nov. 2012.
5. Albakri L, Goldman RD. Permethrin for scabies in children. Can Fam Physician. 2010 Oct;56(10):1005-6.
6. Micromedex. Crotamiton monograph. Available at: http://www.thomsonhc.com/micromedex2/librarian/ND_T/evidencexpert. Accessed October, 2012.
7. Pielop J. Vesiculobullous and pustular lesions in the newborn. UpToDate, Waltham, MA, 2012.
8. Goldstein, BG, Goldstein, AO. Scabies. In: UpToDate, Ofori, AO (Ed), UpToDate, Waltham, MA, 2012.
9. Briggs G, Freeman R, Jason S. Permethrin monograph In: Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, e-book 9th Edition. Lippincott Williams & Wilkins, 2011
10. Schaefer C, Peters P, MillerRK. Drugs During Pregnancy and Lactation, Second Edition. New York: Academic Press; 2007.
11. National Library of Medicine. Permethrin monograph. In: LactMed electronic database. Available at http://toxnet.nlm.nih.gov/cgi-bin/sis/search/f?./temp/~cZGEDf:1. Accessed November, 2012.
12. Scabies monograph. In: Patient.co.uk. Available at http://www.patient.co.uk/health/scabies. Accessed November 2012.
13. Mayoclinic. Scabies. Available at: http://www.mayoclinic.com/health/scabies/DS00451/DSECTION=treatments-and-drugs. Accessed October, 2012.