What is the recommended treatment for scabies in a pediatric patient, including infants under 2 months and older children?

Scabies Treatment in Pediatric Patients

Permethrin 5% cream is the first-line treatment for scabies in all pediatric patients, including infants under 2 months of age, applied from the neck down (and including the scalp, hairline, neck, temple, and forehead in infants and young children), left on for 8-14 hours, then washed off—with one application generally being curative. 1, 2

Treatment by Age Group

Infants Under 2 Months

• Use permethrin 5% cream exclusively as the preferred and safest option, despite off-label status in some regions 1, 3, 4
• Apply to the entire body including scalp, temple, forehead, hairline, and neck (not just neck down as in older children) 2, 1
• Leave on for 8-14 hours before washing off 2
• Studies demonstrate 100% complete resolution in infants under 2 months treated with permethrin, with only mild local eczematous reactions as adverse effects 3, 4
• Avoid ivermectin completely in this age group due to potential neurotoxicity and lack of safety data 1, 5
• Avoid lindane, benzyl alcohol lotion, and malathion due to neurotoxicity risks 1

Infants and Children 2 Months to 10 Years (or <15 kg)

• Permethrin 5% cream remains first-line treatment 6, 1, 7
• Apply from neck down, but include scalp, temple, forehead, hairline, and neck in infants and young children 2, 7
• Use approximately 30 grams for an average adult-sized application; adjust for smaller children 2
• Ivermectin is contraindicated in children weighing <15 kg or under 10 years old due to potential blood-brain barrier penetration and neurotoxicity 5, 1
• Never use lindane in children <10 years due to seizure risk and neurotoxicity 6, 1, 7

Children Over 10 Years (and ≥15 kg)

• Permethrin 5% cream remains first-line 1, 7
• Apply from neck down only (scalp application not needed unless immunocompromised) 2
• Oral ivermectin 200 mcg/kg is an acceptable alternative, repeated in 2 weeks, and must be taken with food to increase bioavailability 5, 1, 7
• Ivermectin is particularly useful when compliance with topical therapy is problematic, in crusted scabies, or in institutional outbreaks 3, 8

Alternative Treatment Options (When Permethrin Unavailable or Failed)

• Sulfur 6% ointment: Apply nightly for 3 consecutive nights, washing off previous applications before reapplying 7
• Crotamiton 10% cream: Apply nightly for 2 consecutive nights, wash off 24 hours after second application 7, 9
  • Note: Crotamiton shows only 60% cure rate at 4 weeks versus 89% for permethrin in children 10
• Benzyl benzoate 25%: Shows 87% cure rate but causes burning sensation in 43% of patients 7

Critical Management Principles

Contact Treatment (Mandatory)

• Treat all household members, sexual partners, and close personal contacts within the preceding month simultaneously, even if asymptomatic 1, 7
• Failure to treat contacts is the most common cause of treatment failure and reinfection 7

Environmental Decontamination

• Machine wash and dry all bedding, clothing, and towels using hot cycles 1, 7
• Alternatively, dry clean or remove items from body contact for at least 72 hours (scabies mites cannot survive >72 hours off human skin) 6, 7
• Fumigation of living areas is unnecessary 1, 7

Expected Post-Treatment Course

• Pruritus and rash may persist for up to 2 weeks after successful treatment due to allergic dermatitis, not treatment failure 6, 5, 1
• Persistent itching alone is not an indication for retreatment 7
• Treat persistent symptoms with topical corticosteroids and oral antihistamines 5

When to Retreat

• Consider retreatment only after 2 weeks if:
  • Live mites are observed on examination 6, 1, 2
  • Symptoms persist beyond 2 weeks 6, 1
  • New lesions continue to appear 1
• Use an alternative regimen if initial treatment fails 6

Special Situations

Crusted (Norwegian) Scabies

• Requires combination therapy with both topical and oral treatment 1, 7
• Permethrin 5% cream applied daily for 7 days, then twice weekly until cure 7
• Plus oral ivermectin 200 mcg/kg on days 1,2,8,9, and 15 1, 7
• Mandatory specialist consultation for management 6, 1

Pregnant or Lactating Women

• Permethrin 5% cream is the preferred treatment due to limited safety data for ivermectin in pregnancy 6, 1, 7
• Ivermectin is classified as "human data suggest low risk" and probably compatible with breastfeeding, but permethrin remains preferred 6, 5

Institutional Outbreaks

• Treat the entire population at risk simultaneously 6, 7
• Consider ivermectin for mass treatment due to ease of administration 6
• Manage in consultation with a specialist 6

Common Pitfalls to Avoid

• Forgetting to apply permethrin to scalp, hairline, temple, and forehead in infants and young children—this is a critical difference from adult application 2, 7
• Failing to treat asymptomatic household contacts simultaneously—leads to reinfection 1, 7
• Retreating too early based on persistent itching alone—wait full 2 weeks before considering retreatment 5, 1
• Using ivermectin without the mandatory second dose at 2 weeks—it has limited ovicidal activity and does not kill eggs 5, 7
• Taking ivermectin without food—significantly reduces bioavailability and epidermal penetration 5, 7
• Using lindane in any child <10 years, pregnant women, or after bathing—increases seizure risk 6, 1, 7