eMedicine Specialties > Dermatology > Parasitic Infections

Scabies: Treatment & Medication

Author: Kelly M Cordoro, MD, Fellow and Clinical Instructor, Department of Pediatric Dermatology, University of California at San Francisco; Assistant Professor (On Educational Leave), Assistant Program Director for Resident Medical Education, Department of Dermatology, University of Virginia School of Medicine
Coauthor(s): Barbara B Wilson, MD, Edward P Cawley Associate Professor, Department of Dermatology, University of Virginia School of Medicine; C Lisa Kauffman, MD, FACP, Professor, Chief, Division of Dermatology, Departments of Medicine and Pathology, Georgetown University Medical Center
Contributor Information and Disclosures

Updated: Nov 12, 2008

Treatment

Medical Care

  • Treatment includes administration of a scabicidal agent, an antipruritic agent such as a sedating antihistamine, and an appropriate antimicrobial agent if secondarily infected.
  • Provision of detailed verbal and written instructions is critical for compliance and complete eradication.
  • All family members and close contacts must be evaluated and treated, even if they do not have symptoms. Pets do not require treatment. All carpets and upholstered furniture should be vacuumed and vacuum bags immediately discarded.
  • Instruct patients to launder clothing, bed linens, and towels used within the last week in hot water the day after treatment is initiated and again in 1 week. Items that cannot be washed may be professionally dry cleaned or sealed in plastic bags for 1 week.
  • Patients with crusted scabies or their caregivers should be instructed to remove excess scale to allow penetration of the topical scabicidal agent and decrease the burden of infestation. This can be achieved with warm water soaks followed by application of a keratolytic agent such as 5% salicylic acid in petrolatum or Lac-Hydrin cream. (Salicylic acid should be avoided if large body surface areas are involved because of the potential risk of salicylate poisoning.) The scales are then mechanically debrided with a tongue depressor or similar nonsharp device.

Consultations

Assessment of immune function may be indicated in individuals presenting with crusted scabies.

Activity

Affected individuals should avoid skin-to-skin contact with others. Decontamination of clothing, bed linens, and other personal items must coincide with medical treatment. Patients with typical scabies may return to school/work 24 hours after the first treatment.

Medication

The mainstay of treatment is the application of topical antiscabietic agents, with repeat application in 7 days. An oral agent, ivermectin, is also available and effective.4,5

Ivermectin is a synthetic macrocyclic lactone belonging to the avermectin group of antibiotics. It has no antibiotic activity but is active against a number of endoparasites and ectoparasites of humans and animals.6 Ivermectin is effective in most cases of typical scabies at a dose of 200-250 mcg/kg given at diagnosis and repeated in 7-14 days. Crusted scabies may require 3 or more doses given at 1- to 2-week intervals. Ivermectin is an ideal agent in cases for which topical therapy is difficult or impractical, such as in widespread institutional infestations and bedridden patients.5

Ivermectin is contraindicated in patients with allergic sensitization or nervous system disorders and in women who are pregnant or breastfeeding. Children younger than 5 years or less than 15 kg should not be treated with ivermectin.

Symptomatic treatment may require oral antihistamines and topical antipruritics/anesthetics such as menthol (Sarna) and pramoxine (Prax). More severe symptoms may require a short course of topical or oral steroids. Secondary infections may require antibiotics and should be prescribed based on culture and sensitivity data.

Scabicides/antiparasitics


Permethrin (Lyclear, Elimite)

Permethrin 5% cream is the drug of choice, especially for infants >2 mo and small children. More effective than crotamiton in treating symptoms and reducing chances of secondary bacterial infection. Even after successful treatment, postscabietic nodules and pruritus may persist for months.

Adult

Apply from chin to toes and under fingernails and toenails; rinse off in shower 12 h later; repeat in 1 wk

Pediatric

>2 months: Apply as in as adults but include head and neck in children <5 y; repeat in 1 wk

Pregnancy

B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals

Precautions

Mild burning or stinging may occur; may exacerbate redness, swelling, and itching, at least temporarily


Lindane (Kwell)

In 1% lotion or cream. Stimulates nervous system of parasite, causing seizures and death. Previously standard treatment for scabies, but now considered second line, to be used if other agents fail or are not tolerated. Not very safe in children or neonates because of transcutaneous absorption leading to neurotoxicity. Overall, permethrin is a safer choice.

Adult

Apply thin layer from chin to toes; use on dry skin and shower off 10 h later; repeat in 1 wk

Pediatric

Not for use in neonates or infants
Children: Apply thin film topically over entire body, including hairline, neck, scalp, temple, and forehead; leave on 6-8 h before washing off with water; may repeat in 1 wk if necessary; not to exceed 30 g per application

Oil-based hairdressings may increase toxicity of lindane

Documented hypersensitivity to lindane products; premature infants; seizure disorders; crusted scabies; other skin conditions (eg, atopic dermatitis, psoriasis) that may increase systemic absorption

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

May cause CNS toxicity; caution if history of seizures; do not apply to eyes, face, or mucous membranes; caution if history of keratinization/ichthyosis disorders


Precipitated sulfur in petrolatum

In 6% concentration.

Adult

Applied to entire body below head on 3 successive nights; bathe 24 h after each application

Pediatric

Administer as in adults, including head and neck

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Available evidence is inconclusive or is inadequate for determining fetal risk when used in pregnant women or women of childbearing potential; weigh potential benefits of drug treatment against potential risks before prescribing during pregnancy


Crotamiton (Eurax)

A 10% cream or lotion for treatment of scabies. Mechanism of action unknown.

Adult

Apply a thin layer onto skin of entire body from neck to toes; repeat application in 24 h; take cleansing bath 48 h after last application

Pediatric

Not FDA approved in pediatric patients

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Do not apply to face, mucous membranes, or swollen, raw, or oozing skin; less effective than lindane; toxicity unknown; discontinue if severe skin irritation develops


Ivermectin (Stromectol)

Binds selectively with glutamate-gated chloride ion channels in invertebrate nerve and muscle cells, causing cell death. Half-life is 16 h; metabolized in liver.
Available in 3- and 6-mg tab.

Adult

200-250 mcg/kg PO at diagnosis; repeat in 7-14 d; crusted scabies may require 3 doses
<120 lb: 12 mg
120-200 lb: 18 mg
>200 lb: 24 mg

Pediatric

<5 years or <15 kg: Not established
>5 years: Administer as in adults

May interact with other ligand-gated chloride channels such as those gated by GABA

Pregnancy

C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus

Precautions

Treat mothers who intend to breastfeed only when risk of delayed treatment outweighs possible risks to newborn caused by ivermectin excretion in milk
Repeat courses of therapy may be required in immunocompromised patients; may cause nausea, vomiting, and mild CNS depression; may cause drowsiness

More on Scabies

Overview: Scabies
Differential Diagnoses & Workup: Scabies
Treatment & Medication: Scabies
Follow-up: Scabies
Multimedia: Scabies
References
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References

  1. Haubrich WS. Medical Meanings: A Glossary of Word Origins. Philadelphia, Pa: American College of Physicians; 1997:200.

  2. Bezold G, Lange M, Schiener R, Palmedo G, Sander CA, Kerscher M, et al. Hidden scabies: diagnosis by polymerase chain reaction. Br J Dermatol. Mar 2001;144(3):614-8. [Medline].

  3. Johnston G, Sladden M. Scabies: diagnosis and treatment. BMJ. Sep 17 2005;331(7517):619-22. [Medline].

  4. Aubin F, Humbert P. Ivermectin for crusted (Norwegian) scabies. N Engl J Med. Mar 2 1995;332(9):612. [Medline].

  5. Huffam SE, Currie BJ. Ivermectin for Sarcoptes scabiei hyperinfestation. Int J Infect Dis. Jan-Mar 1998;2(3):152-4. [Medline].

  6. Elgart GW, Meinking TL. Ivermectin. Dermatol Clin. Apr 2003;21(2):277-82. [Medline].

  7. Brodell RT, Helms SE. Bedside testing: the diagnostic cornerstone of dermatology. Compr Ther. Mar 1997;23(3):211-7. [Medline].

  8. Burgess I. Sarcoptes scabiei and scabies. Adv Parasitol. 1994;33:235-92. [Medline].

  9. Burkhart CG, Burkhart CN, Burkhart KM. An epidemiologic and therapeutic reassessment of scabies. Cutis. Apr 2000;65(4):233-40. [Medline].

  10. Fitzpatrick TB, Austen KF, Wolff K, et al, eds. Dertmatology in General Medicine. 4th ed. New York, NY: McGraw-Hill; 1993:1812-3.

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  12. Fitzpatrick TB, Johnson RA, Wolff K. Inset Bites and Infestations. In: Fitzpatrick TJ, Johnson RA, Wolff K, Polano MK, Suurmond R, eds. Color Atlas and Synopsis of Clinical Dermatology. 3rd ed. New York, NY: McGraw-Hill; 1997:836-61.

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  15. McCarthy JS, Kemp DJ, Walton SF, Currie BJ. Scabies: more than just an irritation. Postgrad Med J. Jul 2004;80(945):382-7. [Medline].

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  17. Orkin M, Maibach HI. Scabies treatment: current considerations. Curr Probl Dermatol. 1996;24:151-6. [Medline].

  18. Paller AS. Scabies in infants and small children. Semin Dermatol. Mar 1993;12(1):3-8. [Medline].

  19. Schleicher SM, Stewart P. Scabies: the mite that roars. Emerg Med. 1997;6:54-8.

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Further Reading

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Keywords

human scabies, seven-year itch, 7-year itch, itch mites, pruritic eruption, Sarcoptes scabiei, S scabiei, Sarcoptes scabiei var hominis, S scabiei var hominis, skin infestation, skin mite, pruritic skin disease, pruritus, crusted scabies, Norwegian scabies, mite infestation

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Contributor Information and Disclosures

Author

Kelly M Cordoro, MD, Fellow and Clinical Instructor, Department of Pediatric Dermatology, University of California at San Francisco; Assistant Professor (On Educational Leave), Assistant Program Director for Resident Medical Education, Department of Dermatology, University of Virginia School of Medicine
Kelly M Cordoro, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Dermatology, American Medical Association, Association of Professors of Dermatology, Dermatology Foundation, Medical Society of Virginia, National Psoriasis Foundation, Society for Pediatric Dermatology, and Women's Dermatologic Society
Disclosure: Nothing to disclose.

Coauthor(s)

Barbara B Wilson, MD, Edward P Cawley Associate Professor, Department of Dermatology, University of Virginia School of Medicine
Barbara B Wilson, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Dermatology, Medical Society of Virginia, and Sigma Xi
Disclosure: Nothing to disclose.

C Lisa Kauffman, MD, FACP, Professor, Chief, Division of Dermatology, Departments of Medicine and Pathology, Georgetown University Medical Center
C Lisa Kauffman, MD, FACP is a member of the following medical societies: American Academy of Dermatology, American Medical Association, Royal Society of Medicine, Society for Investigative Dermatology, and Women's Dermatologic Society
Disclosure: Nothing to disclose.

Medical Editor

Daniel J Hogan, MD, Clinical Professor of Internal Medicine (Dermatology), NOVA Southeastern University; Investigator, Hill Top Research, Florida Research Center
Daniel J Hogan, MD is a member of the following medical societies: Alpha Omega Alpha, American Academy of Dermatology, American Contact Dermatitis Society, and Canadian Dermatology Association
Disclosure: Nothing to disclose.

Pharmacy Editor

Richard P Vinson, MD, Assistant Clinical Professor, Department of Dermatology, Texas Tech University School of Medicine; Consulting Staff, Mountain View Dermatology, PA
Richard P Vinson, MD is a member of the following medical societies: American Academy of Dermatology, Association of Military Dermatologists, Texas Dermatological Society, and Texas Medical Association
Disclosure: Nothing to disclose.

Managing Editor

Paul Krusinski, MD, Director of Dermatology, Professor, Department of Internal Medicine, Fletcher Allen Health Care, University of Vermont
Paul Krusinski, MD is a member of the following medical societies: American Academy of Dermatology, American College of Physicians, and Society for Investigative Dermatology
Disclosure: Nothing to disclose.

CME Editor

Joel M Gelfand, MD, MSCE, Medical Director, Clinical Studies Unit, Assistant Professor, Department of Dermatology, Associate Scholar, Center for Clinical Epidemiology and Biostatistics, University of Pennsylvania
Joel M Gelfand, MD, MSCE is a member of the following medical societies: Society for Investigative Dermatology
Disclosure: AMGEN Consulting fee Consulting; AMGEN Grant/research funds None; Genentech Consulting fee Consulting; Centocor Consulting fee Consulting; Centocor Grant/research funds None; Covance Consulting fee Consulting; Shire  Consulting

Chief Editor

William D James, MD, Paul R Gross Professor of Dermatology, University of Pennsylvania School of Medicine; Vice-Chair, Program Director, Department of Dermatology, University of Pennsylvania Health System
William D James, MD is a member of the following medical societies: American Academy of Dermatology and Society for Investigative Dermatology
Disclosure: elsevier Royalty Other; american college of physicians Honoraria Other

 
 
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