Treatment of scabies in adults and children
To prevent transmission of scabies, consider examining, and treating empirically or as necessary, all members of the patient’s family and close contacts. Also see General measures for scabies for other recommendations to prevent transmission (eg washing clothes).
Topical treatments for scabies should be applied from the neck down. In central and northern Australia and in infants and the elderly, treatment should also be applied to the face and scalp (avoiding the eyes and mucous membranes) because scabies above the neck is common in these patient groups. Treatments for scabies are repeated after 7 days.
Topical permethrin or oral ivermectin are the first line treatments for scabies in children and adultsSalavastru, 2017. They appear to have similar efficacyRosumeck, 2018. The oral dosing of ivermectin may improve adherence over topical permethrin, although this has not been specifically studied. Oral ivermectin cannot be used in children less than 15 kg. In patients who are pregnant or who are breastfeeding, permethrin 5% cream is recommended. Consider practicalities and patient preference when choosing treatment.
To treat scabies in adults and children, use:
1ivermectin (adult and child 15 kg or more) 200 micrograms/kg orally with fatty food. Repeat treatment in 7 days ivermectin ivermectin ivermectin
OR
1permethrin 5% cream (adult and child 6 months or older) topically to dry skin from the neck down, paying particular attention to hands and genitalia. Apply under the nails using a nailbrush. In specific patients1, also apply to the face and scalp (avoiding the eyes and mucous membranes). Leave on for a minimum of 8 hours (usually overnight) and reapply to hands if washed. If there is a history of treatment failure, application time may be increased to 24 hours. Repeat treatment in 7 days. permethrin permethrin permethrin
Benzyl benzoate is effective if used correctly; however, skin irritation occurs more frequently with benzyl benzoate than with permethrin, and this can affect adherence. If ivermectin or permethrin are not tolerated (eg allergy), use:
benzyl benzoate 25% emulsion (child 6 months to 2 years: dilute with 3 parts of water; child 2 to 12 years: dilute with equal parts of water) topically to dry skin from the neck down, paying particular attention to hands and genitalia. Apply under the nails using a nailbrush. In specific patients1, also apply to the face and scalp (avoiding the eyes and mucous membranes). Leave on for 24 hours and reapply to hands if washed. Repeat treatment in 7 days. benzyl benzoate benzyl benzoate benzyl benzoate
If skin irritation occurs in adults with undiluted benzyl benzoate, benzyl benzoate 25% emulsion can be diluted as for child 2 to 12 years.
Immunocompromised patients are more likely to develop crusted scabies. Specialist advice is required; see Treatment of crusted scabies (Norwegian scabies).
Children with scabies, particularly in endemic settings (eg remote communities), are more likely to develop secondary bacterial skin infection, which can lead to acute rheumatic fever. Carefully assess for secondary bacterial infection (eg skin sores, impetigo, pyoderma). If signs of bacterial infection are present, empirical therapy (as for impetigo) is indicated; see Management of impetigo.
Nodules may persist for months after infestation has resolved, despite treatment with a topical corticosteroid. Patients with persistent nodules can be treated with an intralesional corticosteroid.
If treatment with permethrin, oral ivermectin or benzyl benzoate fails, consider an alternative diagnosis or inadequate contact tracing, look for an unidentified source of re-infestation, and check adherence to treatment. Supervised treatment (eg as an inpatient, administered by a community nurse) or specialist referral is recommended. Consider switching treatments (eg if oral ivermectin was used first, try topical permethrin). If therapy still fails, seek specialist advice.