Scabies

Disclaimer These guidelines have been produced to guide clinical decision making for the medical, nursing and allied health staff of Perth Children’s Hospital. They are not strict protocols, and they do not replace the judgement of a senior clinician. Clinical common-sense should be applied at all times. These clinical guidelines should never be relied on as a substitute for proper assessment with respect to the particular circumstances of each case and the needs of each patient. Clinicians should also consider the local skill level available and their local area policies before following any guideline.  Read the full PCH Emergency Department disclaimer.

Aim

To guide PCH ED staff with the assessment and management of scabies.

Definition

Scabies is a skin condition resulting from the infestation of Sarcoptes scabiei scabies mites. 

Background^1,2,3 

• An infestation by Sarcoptes scabiei var. hominis mites causes scabies infection.  Mites are transmitted by skin-to-skin contact, and rarely by fomites such as clothing and bed linen.
• Pruritus is caused by hypersensitivity to the eggs, mites and/or their faeces and usually begins 4-6 weeks after initial infection. Itching can cause a breakdown in the skin barrier predisposing to secondary bacterial infection.
• Scabies infection occurs only in humans. Untreated infection also increases the likelihood of transmission to others.
• Secondary bacterial infection of the skin can result in invasive infection and possible sepsis.  Secondary skin and soft tissue infection due to Streptococcus pyogenes (Group A Streptococcus) can be complicated by acute post streptococcal glomerulonephritis (APSGN) or acute rheumatic fever with progression to chronic kidney disease and rheumatic heart disease, respectively, in some. 

Assessment⁶

• Diagnosis is usually clinical
• Where available, Dermoscopy can be a usual adjunct to visualise mites and burrows in vivo and guide the site for confirmatory skin scrapings.
• The clinical picture of pruritus and primary lesions (burrows, papules, vesicles and pustules) develops at 4-6 weeks after first infestation but within days of subsequent infestations. 
• Burrows (long tracks) are not commonly seen in children
• Pruritus is worse at night, and may manifest as irritability in infants
• Distribution:
  • Scabies mites preferentially infest hairless skin.
  • Facial involvement is uncommon unless immunosuppressed or under one year of age.
  • Infants – usually present with pustules on the palms and soles but can involve the entire body.
  • Children - usually involve web spaces of fingers and toes, flexor surfaces of arms / wrists / axillae and waistline
• Persistent lesions at 1 month after treatment suggest reinfection or persistent infection
• Secondary excoriation and bacterial infection is frequent
• Untreated infection can result in an allergic-type skin rash with the appearance of eczema.  This rash may be widespread, involving the torso and limbs.
• Lichenification may occur with chronic infection.

Management^2,4

See also ChAMP Skin and Soft Tissue Infections

Topical Permethrin 5% cream^5,6

• Permethrin 5% is an anti-parasitic cream applied to the entire body surface (see box below for instructions).
• A second treatment with permethrin 5% should be repeated 1 week after initial treatment as topical permethrin is not ovicidal.
• For Aboriginal and Torres Strait Islander patients, either topical permethrin or oral ivermectin can be prescribed as first line treatment, depending on the family preference. A discussion with the family about the best option for them is important
  • Topical permethrin usually achieves faster symptom resolution than oral ivermectin and is preferred first-line therapy. 
• Asymptomatic household members and close contacts should be treated at the same time to reduce the risk of re-infection.
  • *Note: PCH pharmacy will dispense prescriptions for contacts of paediatric patients – See Provision of chemoprophylaxis to household contacts of communicable diseases - ChAMP.
• Contact Infectious Diseases to discuss treatment in infants less than 6 months old. 
  • Topical crotamiton 10% cream (Eurax^®) is safe and effective for use in young infants < 6 months old and should be considered in this age group if available.¹  
  • Topical permethrin 5% can be used where crotamiton is unavailable.¹

Topical Permethrin 5% Application5,6

Whole body application is recommended for all age groups.  Infants < 6 months old: Leave topical permethrin 5% cream on for 6-8 hours, then wash off with warm, soapy water.  Rinse thoroughly. ≥ 6 months old: Leave topical permethrin 5% cream on for 8-14 hours, then wash off with warm, soapy water.  Rinse thoroughly. Apply the cream to clean, dry skin after a bath or shower, preferably at the end of the day. Start with the face and scalp, avoiding eyes, lips, mouth and mucous membranes. ALWAYS include and pay special attention to: Web spaces of fingers and toes, soles of feet, under nails Body creases - behind ears, under jaw, neck, armpits, genitals, buttocks, under breasts Joints and joint creases - elbows, knees, heels. Apply to entire body surface, not just the lesions. Cream disappears when rubbed gently into skin. Reapply to hands if washed within 8 hours of application. Repeat application to whole body again after 7 days. Most lesions clear after a single application, but a second treatment is still needed. May cause a mild, transient stinging sensation.

Amount6

2-12 months up to one-eighth of a 30 g tube 1-5 years up to one quarter of a 30 g tube. 5-12 years up to half of a 30 g tube. Adults and children >12 years apply up to one 30 g tube (adults may occasionally require an additional tube, but do not apply more than 2 x 30 g tubes)

Safety

Safe for use in pregnancy.2 Australian product information recommends use in infants 6 months or older, however, some respected Australian sources recommend permethrin for children aged  < 2 months, although there is minimal published data to support this.2 Discuss with Infectious Diseases team if scabies is diagnosed in children under 6 months of age.

Ivermectin^4,7,8,9,10

• For children ≥ 10 kg and ≥ 12 months old, oral Ivermectin is an option, especially if topical permethrin is not available.
  • For Aboriginal and Torres Strait Islander patients, either topical permethrin or oral ivermectin can be prescribed as first line treatment, depending on the family preference. A discussion with the family about the best option for them is important.
  • Dose: 0.2 mg/kg PO as a single dose.  Repeat the dose in 7 days as oral ivermectin is not ovicidal.

Suggested dose bands: 

Weight (and ≥ 12 months old)	Rounded dose
10 – 24 kg	3 mg (1 tablet)
25 – 35 kg	6 mg (2 tablets)
36 – 50 kg	9 mg (3 tablets)
51 – 65 kg	12 mg (4 tablets)
66 – 79 kg	15 mg (5 tablets)
≥ 80 kg	0.2 mg/kg

Further management^1,2

• Pruritus frequently takes one week or longer to resolve after treatment.
  • Calamine lotion (available without prescription) may be indicated to control itch until symptoms resolve.
  • Antihistamines may help to control itching
  • In patients with debilitating pruritus a short course of topical corticosteroids can be helpful.
• Look for and provide treatment of secondary bacterial infection (impetigo): Mupirocin 2% ointment can be used to treat a small number (<3) of localised lesions or refer to the Skin and Soft Tissue Infections - ChAMP guideline if oral antibiotics are required for extensive infection.
• Bed linen and clothing should be washed in hot water and sun dried.
• For items where this is not possible, they should be ironed or stored in a sealed plastic bag for 72 hours.
• Carpets and fabric furniture in the home should also be vacuumed. 
• Children should not attend school until the first treatment dose has been completed.  Any open sores should be covered and treated with topical or oral antibiotics.

Nursing

• Contact precautions - gloves and long sleeve gowns.
• Place all linen in a plastic bag and then into the usual laundry bag.

References

1. National Healthy Skin Guideline: national-healthy-skin-guideline---1st-ed.-2018.pdf (thekids.org.au)
2. Australian Medication Handbook Children's Dosing Companion, Australian Medicines Handbook Pty Ltd, 2021. Mupirocin. Modified July 2021. Cited 4 November 2021. Available from: Mupirocin - AMH Children's Dosing Companion (health.wa.gov.au)
3. Australian Medication Handbook Children's Dosing Companion, Australian Medicines Handbook Pty Ltd, 2021. Permethrin. Modified July 2021. Cited 4 November 2021. Available from: Permethrin - AMH Children's Dosing Companion (health.wa.gov.au)
4. Lyclear® patient information leaflet, Johnson & Johnson Pacific Pty Limited.
5. Rossi S, Pharmaceutical Society of Australia, Australasian Society of Clinical and Experimental Pharmacologists and Toxicologists, Royal Australian College of General Practitioners. Australian Medicines Handbook 2021. Available from: https://amhonline-amh-net-au.pklibresources.health.wa.gov.au/chapters/dermatological-drugs/scabicides-pediculicides/permethrin
6. Chandler DJ & Fuller LC, A Review of Scabies: An Infestation More than Skin Deep. Dermatology 2019;235:79–90

Endorsed by:	Executive Director, Medical Services	Date:	Mar 2025
		Review date:	Mar 2029

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